Eldorado Collection:
http://hdl.handle.net/2003/24987
2024-07-12T20:34:22ZQuantitative complementarity between local and nonlocal character of quantum states in a three-qubit system
http://hdl.handle.net/2003/25409
Title: Quantitative complementarity between local and nonlocal character of quantum states in a three-qubit system
Authors: Suter, Dieter; Peng, Xinhua; Zhang, Jingfu; Du, Jiangfeng
Abstract: Local or nonlocal character of quantum states can be quantified and is subject to various bounds that can be formulated as complementarity relations. Here, we investigate the local vs nonlocal character of pure three-qubit states by a four-way interferometer. The complete entanglement in the system can be measured as the entanglement of a specific qubit with the subsystem consisting of the other two qubits. The quantitative complementarity relations are verified experimentally in an NMR quantum information processor.2008-05-08T00:00:00ZDetection of Quantum Critical Points by a Probe Qubit
http://hdl.handle.net/2003/25408
Title: Detection of Quantum Critical Points by a Probe Qubit
Authors: Suter, Dieter; Zhang, Jingfu; Peng, Xinhua; Rajendran, Nageswaran
Abstract: Quantum phase transitions occur when the ground state of a quantum system undergoes a qualitative change when an external control parameter reaches a critical value. Here, we demonstrate a technique for studying quantum systems undergoing a phase transition by coupling the system to a probe qubit. It uses directly the increased sensibility of the quantum system to perturbations when it is close to a critical point. Using an NMR quantum simulator, we demonstrate this measurement technique for two different types of quantum phase transitions in an Ising spin chain.2008-03-13T00:00:00ZQuantum Computing
http://hdl.handle.net/2003/25407
Title: Quantum Computing
Authors: Suter, Dieter; Stolze, Joachim2008-01-01T00:00:00ZExperimental observation of a topological phase in the maximally entangled state of a pair of qubits
http://hdl.handle.net/2003/25406
Title: Experimental observation of a topological phase in the maximally entangled state of a pair of qubits
Authors: Suter, Dieter; Du, Jiangfeng; Zhu, Jing; Shi, Mingjun; Peng, Xinhua
Abstract: Quantum mechanical phase factors can be related to dynamical effects or to the geometrical properties of a trajectory in a given space—either parameter space or Hilbert space. Here, we experimentally investigate a quantum mechanical phase factor that reflects the topology of the SO(3) group: since rotations by pi around antiparallel axes are identical, this space is doubly connected. Using a pair of nuclear spins in a maximally entangled state, we subject one of the spins to a cyclic evolution. If the corresponding trajectory in SO(3) can be smoothly deformed to a point, the quantum state at the end of the trajectory is identical to the initial state. For all other trajectories the quantum state changes sign.2007-10-22T00:00:00ZMeasuring complete quantum states with a single observable
http://hdl.handle.net/2003/25405
Title: Measuring complete quantum states with a single observable
Authors: Suter, Dieter; Peng, Xinhua; Du, Jiangfeng
Abstract: Experimental determination of an unknown quantum state usually requires several incompatible measurements. However, it is also possible to determine the full quantum state from a single, repeated measurement. For this purpose, the quantum system whose state is to be determined is first coupled to a second quantum system (the “assistant”) in such a way that part of the information in the quantum state is transferred to the assistant. The actual measurement is then performed on the enlarged system including the original system and the assistant. We discuss in detail the requirements of this procedure and experimentally implement it on a simple quantum system consisting of nuclear spins.2007-10-13T00:00:00ZEvolution of Athletic Records
http://hdl.handle.net/2003/25404
Title: Evolution of Athletic Records
Authors: Suter, Dieter; Gembris, Daniel; Taylor, John G.
Abstract: Athletic records represent the best results in a given discipline, thus improving monotonically with time. As has already been shown, this should not be taken as an indication that the athletes' capabilities keep improving. In other words, a new record is not noteworthy just because it is a new record, instead it is necessary to assess by how much the record has improved. In this paper we derive formulae that can be used to show that athletic records continue to improve with time, even if athletic performance remains constant. We are considering two specific examples, the German championships and the world records in several athletic disciplines. The analysis shows that, for the latter, true improvements occur in 20-50% of the disciplines. The analysis is supplemented by an application of our record estimation approach to the prediction of the maximum body length of humans for a specified size of a population respectively population group from a representative sample.2007-07-01T00:00:00ZIterative quantum-state transfer along a chain of nuclear spin qubits
http://hdl.handle.net/2003/25403
Title: Iterative quantum-state transfer along a chain of nuclear spin qubits
Authors: Suter, Dieter; Zhang, Jingfu; Rajendran, Nageswaran; Peng, Xinhua
Abstract: Transferring quantum information between two qubits is a basic requirement for many applications in quantum communication and quantum-information processing. In the iterative quantum-state transfer proposed by Burgarth et al. [Phys. Rev. A 75, 062327 (2007)], this is achieved by a static spin chain and a sequence of gate operations applied only to the receiving end of the chain. The only requirement on the spin chain is that it transfers a finite part of the input amplitude to the end of the chain, where the gate operations accumulate the information. For an appropriate sequence of evolutions and gate operations, the fidelity of the transfer can asymptotically approach unity. We demonstrate the principle of operation of this transfer scheme by implementing it in a nuclear magnetic resonance quantum-information processor.2007-07-17T00:00:00ZFactorizing numbers with the Gauss sum technique
http://hdl.handle.net/2003/25402
Title: Factorizing numbers with the Gauss sum technique
Authors: Suter, Dieter; Mahesh, T. S.; Rajendran, Nageswaran; Peng, Xinhua
Abstract: Several physics-based algorithms for factorizing large numbers were recently presented. A notable recent algorthm by Schleich et al. uses Gauss sums for distinguishing between factors and nonfactors. We demonstrate two NMR techniques that evaluate Gauss sums and thus implement their algorithm. The first one is based on differential excitation of a single spin magnetization by a cascade of rf pulses. The second method is based on spatial averaging and selective refocusing of magnetization for Gauss sums corresponding to factors. All factors of 16 637 and 52 882 363 are successfully obtained.2007-06-04T00:00:00ZEffect of system level structure and spectral distribution of the environment on the decoherence rate
http://hdl.handle.net/2003/25401
Title: Effect of system level structure and spectral distribution of the environment on the decoherence rate
Authors: Suter, Dieter; Zhang, Jingfu; Peng, Xinhua; Rajendran, Nageswaran
Abstract: Minimizing the effect of decoherence on a quantum register must be a central part of any strategy to realize scalable quantum-information processing. Apart from the strength of the coupling to the environment, the decoherence rate is determined by the system level structure and by the spectral composition of the noise trace that the environment generates. Here, we discuss a relatively simple model that allows us to study these different effects quantitatively in detail. We evaluate the effect that the perturbation has on a nuclear magnetic resonance system while it performs a Grover search algorithm.2007-04-13T00:00:00ZDecoherence in large quantum registers under variable interaction with the environment
http://hdl.handle.net/2003/25400
Title: Decoherence in large quantum registers under variable interaction with the environment
Authors: Suter, Dieter; Lovric, Marko; Krojanski, Hans G.
Abstract: Effective quantum-information processing requires coherent control of large numbers of qubits on a time scale that is short compared to the decoherence time of the system. It is therefore important to extrapolate and measure decoherence times for large quantum registers and to determine the effect of different couplings between system and environment on the decoherence rate. For this purpose, we have experimentally realized a system that allows one to generate model quantum registers with more than 100 qubits and measure the decay of the information in these states while adjusting the strength of the interaction between the quantum register and the environment. Our results indicate a power-law dependence of the decoherence rate on the number of qubits in the system, with an exponent of the order of 0.5. This behavior remains qualitatively unchanged when the coupling strength to the environment is reduced by about an order of magnitude.2007-04-03T00:00:00ZSpins as probes of different electronic states
http://hdl.handle.net/2003/25399
Title: Spins as probes of different electronic states
Authors: Suter, Dieter; Klieber, Robert
Abstract: Nuclear spins are efficient probes of electronic states. Because most NMR experiments are performed in thermal equilibrium, they probe the electronic ground state - the only state that is significantly populated under ambient conditions. Probing electronically excited states becomes possible, if magnetic resonance techniques are combined with optical (laser) excitation. Depending on the nature of the electronic state, drastic changes of the magnetic resonance parameters may be observed. We discuss the basic principles of this type of investigation. Depending on the lifetime of the electronically excited state, it is possible to measure separate spectra of ground and excited state if the lifetime is long on the NMR timescale, or an averaged spectrum if the lifetime is short. We present examples for both limiting cases using rare earth ions and semiconductor heterostructures.2007-03-01T00:00:00ZTwo-qubit gates between noninteracting qubits in endohedral-fullerene-based quantum computation
http://hdl.handle.net/2003/25398
Title: Two-qubit gates between noninteracting qubits in endohedral-fullerene-based quantum computation
Authors: Suter, Dieter; Du, Jiangfeng; Ju, Chenyong2007-01-17T00:00:00ZExperimental realization of 1 --> 2 asymmetric phase-covariant quantum cloning
http://hdl.handle.net/2003/25397
Title: Experimental realization of 1 --> 2 asymmetric phase-covariant quantum cloning
Authors: Suter, Dieter; Cheng, Hongwei; Zhou, Xianyi; Du, Jiangfeng
Abstract: While exact cloning of an unknown quantum state is prohibited by the linearity of quantum mechanics, approximate cloning is possible and has been used, e.g., to derive limits on the security of quantum communication protocols. In the case of asymmetric cloning, the information from the input state is distributed asymmetrically between the different output states. Here, we consider asymmetric phase-covariant cloning, where the goal is to optimally transfer the phase information from a single input qubit to different output qubits. We construct an optimal quantum cloning machine for two qubits that does not require ancilla qubits and implement it on an NMR quantum information processor.2007-01-17T00:00:00ZDecoherence in large NMR quantum registers
http://hdl.handle.net/2003/25396
Title: Decoherence in large NMR quantum registers
Authors: Suter, Dieter; Krojanski, Hans Georg2006-12-26T00:00:00ZQuantum-information processing using strongly dipolar coupled nuclear spins
http://hdl.handle.net/2003/25395
Title: Quantum-information processing using strongly dipolar coupled nuclear spins
Authors: Suter, Dieter; Mahesh, T. S.
Abstract: Dipolar coupled homonuclear spins present challenging, yet useful systems for quantum-information processing. In such systems, the eigenbasis of the system Hamiltonian is the appropriate computational basis and coherent control can be achieved by specially designed strongly modulating pulses. In this paper we describe the first experimental implementation of the quantum algorithm for numerical gradient estimation by nuclear magnetic resonance, using the eigenbasis of a four spin system.2006-12-18T00:00:00ZReduced Decoherence in Large Quantum Registers
http://hdl.handle.net/2003/25394
Title: Reduced Decoherence in Large Quantum Registers
Authors: Suter, Dieter; Krojanski, Hans G.
Abstract: Among the biggest obstacles for building larger (and thus more powerful) quantum-information processors is decoherence, the decay of quantum-information by the coupling between the quantum register and its environment. Procedures for reducing decoherence processes will be essential for successful operation of larger quantum processors. We study model quantum registers consisting of up to 4900 qubits and measure their decay as a function of the register size. We demonstrate that appropriate sequences of qubit rotations reduce the coupling between system and environment for all sizes of the quantum register, thus preserving the quantum-information 50 times longer than without decoupling.2006-10-11T00:00:00ZSpeedup of quantum-state transfer by three-qubit interactions
http://hdl.handle.net/2003/25393
Title: Speedup of quantum-state transfer by three-qubit interactions
Authors: Suter, Dieter; Zhang, Jingfu; Peng, Xinhua
Abstract: Universal quantum information processing requires single-qubit rotations and two-qubit interactions as minimal resources. A possible step beyond this minimal scheme is the use of three-qubit interactions. We consider such three-qubit interactions and show how they can reduce the time required for a quantum state transfer in an XY spin chain. For the experimental implementation, we use liquid-state nuclear magnetic resonance, where three-qubit interactions can be implemented by sequences of radio-frequency pulses.2006-06-19T00:00:00ZLaser-assisted magnetic resonance: principles and applications
http://hdl.handle.net/2003/25392
Title: Laser-assisted magnetic resonance: principles and applications
Authors: Suter, Dieter; Gutschank, J.
Abstract: Laser radiation can be used in various magnetic resonance experiments. This chapter discusses a number of cases, where laser light either improves the information content of conventional experiments or makes new types of experiments possible, which could not be performed with conventional means. Sensitivity is often the main reason for using light, but it also allows one to become more selective, e.g. by selecting signals only from small parts of the sample. Examples are given for NMR, NQR, and EPR spectra that use were taken with the help of coherent optical radiation.2006-09-11T00:00:00ZAdding salt to an aqueous solution of t-butanol
http://hdl.handle.net/2003/25391
Title: Adding salt to an aqueous solution of t-butanol
Authors: Suter, Dieter; Paschek, Dietmar; Geiger, Alfons; Herve, Momo J.
Abstract: Recent neutron scattering experiments on aqueous salt solutions of amphiphilic t-butanol by Bowron and Finney [Phys. Rev. Lett. 89, 215508 (2002); J. Chem. Phys. 118, 8357 (2003)] suggest the formation of t-butanol pairs, bridged by a chloride ion via O–H[centered ellipsis]Cl– hydrogen bonds, leading to a reduced number of intermolecular hydrophobic butanol-butanol contacts. Here we present a joint experimental/theoretical study on the same system, using a combination of molecular dynamics (MD) simulations and nuclear magnetic relaxation measurements. Both MD simulation and experiment clearly support the more classical scenario of an enhanced number of hydrophobic contacts in the presence of salt, as it would be expected for purely hydrophobic solutes. [T. Ghosh et al., J. Phys. Chem. B 107, 612 (2003)]. Although our conclusions arrive at a structurally completely distinct scenario, the molecular dynamics simulation results are within the experimental error bars of the Bowron and Finney data.2006-04-21T00:00:00ZTime-resolved coherent double Raman detection of nuclear spin transitions
http://hdl.handle.net/2003/25390
Title: Time-resolved coherent double Raman detection of nuclear spin transitions
Authors: Suter, Dieter; Klieber, Robert
Abstract: Coherent Raman scattering can be used for detection of nuclear spin transitions in solids and atomic vapors if both nuclear spin states of the spin transition to be detected are connected to a single nuclear spin state of a different electronic state by allowed optical transitions. This is not the case in crystals with high symmetry. Here, we introduce the coherent double Raman experiment, where the difference between nuclear spin transitions in two different electronic states is observed. In contrast to the conventional Raman scattering experiment, this scheme is applicable also to systems with high symmetry, where the nuclear spin does not change during an optical transition.2006-03-08T00:00:00ZQuantification of complementarity in multi-qubit systems
http://hdl.handle.net/2003/25389
Title: Quantification of complementarity in multi-qubit systems
Authors: Suter, Dieter; Peng, Xianhua; Xhu, Ziewen; Du, Jiangfeng; Liu, Maili; Gao, Kelin
Abstract: Complementarity was originally introduced as a qualitative concept for the discussion of properties of quantum mechanical objects that are classically incompatible. More recently, complementarity has become a quantitative relation between classically incompatible properties, such as the visibility of interference fringes and "which-way" information, but also between purely quantum mechanical properties, such as measures of entanglement. We discuss different complementarity relations for systems of two-, three-, or n qubits. Using nuclear magnetic resonance techniques, we have experimentally verified some of these complementarity relations in a two-qubit system.2005-11-16T00:00:00ZAutler-Townes effect in a strongly driven electromagnetically induced transparency resonance
http://hdl.handle.net/2003/25388
Title: Autler-Townes effect in a strongly driven electromagnetically induced transparency resonance
Authors: Suter, Dieter; Yang, Lijun; Zhang, Lianshui; Li, Xiaoli; Han, Li; Fu, Guangsheng; Manson, Neil B.; Wei, Chiangjiang2005-11-01T00:00:00ZEfficient implementations of the quantum Fourier transform
http://hdl.handle.net/2003/25387
Title: Efficient implementations of the quantum Fourier transform
Authors: Suter, Dieter; Dorai, Kavita
Abstract: The Quantum Fourier transform (QFT) is a key ingredient in most quantum algorithms. We have compared various spin-based quantum computing schemes to implement the QFT from the point of view of their actual time-costs and the accuracy of the implementation. We focus here on an interesting decomposition of the QFT as a product of the non-selective Hadamard transformation followed by multiqubit gates corresponding to square- and higher-roots of controlled-NOT gates. This decomposition requires only O(n) operations and is thus linear in the number of qubits n. The schemes were implemented on a two-qubit NMR quantum information processor and the resultant density matrices reconstructed using standard quantum state tomography techniques. Their experimental fidelities have been measured and compared.2005-06-01T00:00:00ZPlanar microresonators for EPR experiments
http://hdl.handle.net/2003/25386
Title: Planar microresonators for EPR experiments
Authors: Suter, Dieter; Narkowicz, R.; Stonies, R.2005-06-06T00:00:00ZCorrelating NQR transitions of ground and excited electronical states
http://hdl.handle.net/2003/25385
Title: Correlating NQR transitions of ground and excited electronical states
Authors: Suter, Dieter; Klieber, Robert2005-06-24T00:00:00ZExperimental demonstration of efficient and selective population transfer and qubit distillation in a rare-earth-metal-ion-doped crystal
http://hdl.handle.net/2003/25384
Title: Experimental demonstration of efficient and selective population transfer and qubit distillation in a rare-earth-metal-ion-doped crystal
Authors: Suter, Dieter; Klieber, Robert; Rippe, Lars; Nilsson, Mattias; Kröll, Stefan
Abstract: In optically controlled quantum computers it may be favorable to address different qubits using light with different frequencies, since the optical diffraction does not then limit the distance between qubits. Using qubits that are close to each other enables qubit-qubit interactions and gate operations that are strong and fast in comparison to qubit-environment interactions and decoherence rates. However, as qubits are addressed in frequency space, great care has to be taken when designing the laser pulses, so that they perform the desired operation on one qubit, without affecting other qubits. Complex hyperbolic secant pulses have theoretically been shown to be excellent for such frequency-addressed quantum computing [I. Roos and K. Molmer, Phys. Rev. A 69, 022321 (2004)]—e.g., for use in quantum computers based on optical interactions in rare-earth-metal-ion-doped crystals. The optical transition lines of the rare-earth-metal-ions are inhomogeneously broadened and therefore the frequency of the excitation pulses can be used to selectively address qubit ions that are spatially separated by a distance much less than a wavelength. Here, frequency-selective transfer of qubit ions between qubit states using complex hyperbolic secant pulses is experimentally demonstrated. Transfer efficiencies better than 90% were obtained. Using the complex hyperbolic secant pulses it was also possible to create two groups of ions, absorbing at specific frequencies, where 85% of the ions at one of the frequencies was shifted out of resonance with the field when ions in the other frequency group were excited. This procedure of selecting interacting ions, called qubit distillation, was carried out in preparation for two-qubit gate operations in the rare-earth-metal-ion-doped crystals. The techniques for frequency-selective state-to-state transfer developed here may be also useful also for other quantum optics and quantum information experiments in these long-coherence-time solid-state systems.2005-06-23T00:00:00ZLight-induced Knight shifts in GaAs/AlGaAs quantum wells
http://hdl.handle.net/2003/25383
Title: Light-induced Knight shifts in GaAs/AlGaAs quantum wells
Authors: Suter, Dieter; Fustmann, S.; Eickhoff, M.
Abstract: The coupling between quantum-confined electron spins in semiconductor heterostructures and nuclear spins dominates the dephasing of spin qubits in III/V semiconductors. The interaction can be measured through the electron-spin dynamics or through its effect on the nuclear spin. Here, we discuss the resulting shift of the NMR frequency (the Knight shift) and measure its size as a function of the charge-carrier density for photoexcited charge carriers in a GaAs quantum well.2005-05-31T00:00:00ZQuantum and classical parallelism in parity algorithms for ensemble quantum computers
http://hdl.handle.net/2003/25382
Title: Quantum and classical parallelism in parity algorithms for ensemble quantum computers
Authors: Suter, Dieter; Banzhaf, Wolfgang; Stadelhofer, Ralf2005-03-28T00:00:00ZHigh resolution spectroscopy of yellow 1S excitons in Cu2O
http://hdl.handle.net/2003/25381
Title: High resolution spectroscopy of yellow 1S excitons in Cu2O
Authors: Suter, Dieter; Fröhlich, D.; Dasbach, G.; Baldassari Höger von Högersthal, G.; Stolz, H.; Bayer, M.; Klieber, R.2004-12-13T00:00:00ZAnisotropic effective exciton mass in Cu2O
http://hdl.handle.net/2003/25380
Title: Anisotropic effective exciton mass in Cu2O
Authors: Suter, Dieter; Dasbach, G.; Fröhlich, D.; Stolz, H.; Klieber, R.; Bayer, M.2005-02-10T00:00:00ZQuantum phase transition of ground-state entanglement in a Heisenberg spin chain simulated in an NMR quantum computer
http://hdl.handle.net/2003/25379
Title: Quantum phase transition of ground-state entanglement in a Heisenberg spin chain simulated in an NMR quantum computer
Authors: Suter, Dieter; Peng, Xinhua; Du, Jiangfeng
Abstract: Using an NMR quantum computer, we experimentally simulate the quantum phase transition of a Heisenberg spin chain. The Hamiltonian is generated by a multiple-pulse sequence, the nuclear-spin system is prepared in its (pseudopure) ground state, and the effective Hamiltonian varied in such a way that the Heisenberg chain is taken from a product state to an entangled state, and finally to a different product state.2005-01-05T00:00:00ZHole-burning techniques for isolation and study of individual hyperfine transitions in inhomogeneously broadened solids demonstrated in Pr3+:Y2SiO5
http://hdl.handle.net/2003/25378
Title: Hole-burning techniques for isolation and study of individual hyperfine transitions in inhomogeneously broadened solids demonstrated in Pr3+:Y2SiO5
Authors: Suter, Dieter; Nilsson, M.; Rippe, L.; Kröll, S.; Klieber, R.2004-12-30T00:00:00ZScaling of decoherence in wide quantum registers
http://hdl.handle.net/2003/25377
Title: Scaling of decoherence in wide quantum registers
Authors: Suter, Dieter; Krojanski, Hans G.
Abstract: Among the most important parameters for the usefulness of quantum computers are the size of the quantum register and the decoherence time for the quantum information. The decoherence time is expected to get shorter with the number of correlated qubits, but experimental data are only available for small numbers of qubits. Solid-state nuclear magnetic resonance allows one to correlate large numbers of qubits (several hundred) and measure their decoherence rates. We use a modified magnetic dipole-dipole interaction to correlate the proton spins in a solid sample and observe the decay of the resulting highly correlated states. By systematically varying the number of correlated spins, we measure the increase of the decoherence rate with the size of the quantum register.2004-08-24T00:00:00ZWave-vector-dependent exchange interaction and its relevance for the effective exciton mass in Cu2O
http://hdl.handle.net/2003/25376
Title: Wave-vector-dependent exchange interaction and its relevance for the effective exciton mass in Cu2O
Authors: Suter, Dieter; Klieber, R.; Fröhlich, D.; Stolz, H.; Dasbach, G.; Bayer, M.2004-07-27T00:00:00ZQuantum Computing
http://hdl.handle.net/2003/25375
Title: Quantum Computing; A Short Course from Theory to Experiment
Authors: Suter, Dieter; Stolze, Joachim2004-01-01T00:00:00ZOrientational Information from Unoriented Metalloproteins by Optically Detected Electron Paramagnetic Resonance
http://hdl.handle.net/2003/25374
Title: Orientational Information from Unoriented Metalloproteins by Optically Detected Electron Paramagnetic Resonance
Authors: Suter, Dieter; Enkisch, Birgit; Gutschank, Jörg
Abstract: The electronic structure of metalloproteins can be analysed with optically detected electron paramagnetic resonance (ODEPR). This relatively young technique combines electron paramagnetic resonance (EPR) and magnetic circular dichroism (MCD) with a coherent Raman scattering experiment. It can complement conventional EPR and MCD in the deconvolution and assignment of optical transitions. Information about the relative orientation of optical and magnetic transition dipoles in metalloproteins can be extracted with considerably higher resolution than by alternative techniques such as MCD. We discuss how these features provide information about the environment of metal ions in metalloproteins.2004-01-01T00:00:00ZPulsed optically detected NMR of single GaAs/AlGaAs Quantum Wells
http://hdl.handle.net/2003/25373
Title: Pulsed optically detected NMR of single GaAs/AlGaAs Quantum Wells
Authors: Suter, Dieter; Eickhoff, Marcus
Abstract: While nuclear magnetic resonance (NMR) is one of the most important experimental tools for the analysis of bulk materials, the low sensitivity of conventional NMR makes it unsuitable for the investigation of small structures. We introduce an experimental scheme that makes NMR spectra of single, nanometer-sized quantum wells possible with excellent sensitivity and selectivity while avoiding the spectral broadening associated with some alternative techniques. The scheme combines optical pumping and pulsed radiofrequency excitation of the nuclei with time-resolved detection of the free induction decay through the polarization of the photoluminescence.2003-11-06T00:00:00ZWave-Vector-Dependent Exciton Exchange Interaction
http://hdl.handle.net/2003/25372
Title: Wave-Vector-Dependent Exciton Exchange Interaction
Authors: Suter, Dieter; Dasbach, G.; Fröhlich, D.; Klieber, R.; Stolz, H.; Bayer, M.2003-09-04T00:00:00ZAll-optical measurement of nuclear-spin relaxation. In: Physical Reviews
http://hdl.handle.net/2003/25371
Title: All-optical measurement of nuclear-spin relaxation. In: Physical Reviews
Authors: Suter, Dieter; Klieber, Robert; Michalowski, Andreas; Neuhaus, Rudolf2003-08-26T00:00:00ZK-dependent Exchange Interaction of Quadrupole Excitons in Cu2O
http://hdl.handle.net/2003/25370
Title: K-dependent Exchange Interaction of Quadrupole Excitons in Cu2O
Authors: Suter, Dieter; Klieber, R.; Dasbach, G.; Fröhlich, D.; Stolz, D.; Bayer, M.2003-07-24T00:00:00ZNuclear quadrupole resonance of an electronically excited state from high-resolution hole-burning spectroscopy
http://hdl.handle.net/2003/25369
Title: Nuclear quadrupole resonance of an electronically excited state from high-resolution hole-burning spectroscopy
Authors: Suter, Dieter; Michalowski, Andreas; Klieber, Robert; Neuhaus, Rudolf2003-05-05T00:00:00ZSize scaling of decoherence rates
http://hdl.handle.net/2003/25368
Title: Size scaling of decoherence rates
Authors: Suter, Dieter; Meierle, C. S.2003-01-01T00:00:00ZMapping of strain and electric fields in GaAs/AlGaAs quantum-well samples by laser-assisted NMR
http://hdl.handle.net/2003/25367
Title: Mapping of strain and electric fields in GaAs/AlGaAs quantum-well samples by laser-assisted NMR
Authors: Suter, Dieter; Lenzmann, Björn; Eickhoff, Marcus; Hayes, Sophia E.; Wieck, Andreas D.
Abstract: The usefulness of semiconductor heterostructures derives from the possibility to engineer their electronic and optical properties to match the requirements of many different applications. Optically detected nuclear magnetic resonance provides the possibility to map microscopic properties of such samples with a high spatial resolution through the splitting of resonance lines. In a multiple quantum-well sample, we measure the distortion of the crystal lattice and find variations of the order of 10^(-5) over distances of a few mm. Internal electric fields also cause resonance line splittings. Comparing the electric field-induced resonance line splittings in different quantum wells, we mapped the vertical variation of the electric field from a Schottky contact with a spatial resolution of some 40 nm.2003-02-06T00:00:00ZF Centers in LiF
http://hdl.handle.net/2003/25366
Title: F Centers in LiF
Authors: Suter, Dieter; Klempt, Thomas; Kanert, O.2003-02-06T00:00:00ZMagneto-optical and EPR transitions in Raman heterodyne spectroscopy
http://hdl.handle.net/2003/25365
Title: Magneto-optical and EPR transitions in Raman heterodyne spectroscopy
Authors: Suter, Dieter; Schweika-Kresimon, Marc O.; Gutschank, Jörg
Abstract: Laser and microwave fields can be mixed in paramagnetic samples in a coherent Raman process. The radiation scattered in the forward direction contains frequency components at the sum and difference frequency. We consider the details of this scattering process in a static magnetic field, where two types of signals appear: magnetic-resonance transitions give rise to signals at fixed magnetic fields, independent of the laser frequency. Another set of resonances is determined by the optical transition frequencies. These resonances are particularly prominent in samples with narrow optical absorption lines. We derive a comprehensive theory that describes both contributions and compare it with experimental data from the R lines of ruby.2002-10-30T00:00:00ZSynthesis and Molecular Structure of a Tricyclic Stannasiloxane Containing a Novel SiSn3O3F2 Structural Motif
http://hdl.handle.net/2003/25364
Title: Synthesis and Molecular Structure of a Tricyclic Stannasiloxane Containing a Novel SiSn3O3F2 Structural Motif
Authors: Suter, Dieter; Beckmann, J.; Jurkschat, K.; Schürmann, M.; Willem, R.
Abstract: The synthesis of the fluorine-substituted stannasiloxane complex cyclo-Ph2Si(OSnt-Bu2)2O·t-Bu2SnF2 (7) is reported, and its molecular structure has been determined by single-crystal X-ray diffraction analysis.2002-08-06T00:00:00ZArchitectures for a Spin Quantum Computer Based on Endohedral Fullerenes
http://hdl.handle.net/2003/25363
Title: Architectures for a Spin Quantum Computer Based on Endohedral Fullerenes
Authors: Suter, Dieter; Harneit, W.; Meyer, C.; Weidinger, A.; Twamley, J.
Abstract: We present a discussion of recent concepts for the construction of a spin quantum computer using endohedral fullerenes. The fullerene molecule is a static, room-temperature trap for atoms with slowly relaxing electron and nuclear spins. The fullerene containers can be used to arrange the spins in complex structures such as a linear chain, to form a spin quantum register. We discuss the probable properties of such registers and different strategies to use them in a quantum computer design, including gating and read-out methods.2002-09-26T00:00:00ZTrends and random fluctuations in athletics
http://hdl.handle.net/2003/25362
Title: Trends and random fluctuations in athletics
Authors: Suter, Dieter; Gembris, Daniel; Taylor, John G.
Abstract: Improvements in the results of athletic competitions are often considered to stem from better training and equipment, but elements of chance are always present in athletics and these also contribute. Here we distinguish between these two effects by estimating the range into which athletic records would have fallen in the absence of systematic progress and then comparing this with actual performance results. We find that only 4 out of 22 disciplines have shown a systematic improvement, and that annual best results worldwide1 show saturation in some disciplines.2002-05-30T00:00:00ZA scalable architecture for spin-based quantum computers with a single type of gates.
http://hdl.handle.net/2003/25361
Title: A scalable architecture for spin-based quantum computers with a single type of gates.
Authors: Suter, Dieter; Lim, Kyungwon2002-04-24T00:00:00ZCoupling mechanisms for optically induced NMR in GaAs quantum wells
http://hdl.handle.net/2003/25360
Title: Coupling mechanisms for optically induced NMR in GaAs quantum wells
Authors: Suter, Dieter; Eickhoff, Marcus; Lenzman, Björn; Flinn, Gregory2002-02-13T00:00:00ZA first-principles approach for diffusion tensor based fiber tracking
http://hdl.handle.net/2003/25358
Title: A first-principles approach for diffusion tensor based fiber tracking
Authors: Suter, Dieter; Gembris, Daniel; Schumacher, Helmut; Zilles, Karl2004-02-03T00:00:00ZMagnetic resonance investigation of F centers in LiF caused by ionizing radiation
http://hdl.handle.net/2003/25357
Title: Magnetic resonance investigation of F centers in LiF caused by ionizing radiation
Authors: Suter, Dieter; Schweizer, S.; Schwartz, K.; Kanert, O.; Rogulis, U.; Spaeth, J.-M.2001-11-04T00:00:00ZMagnetic resonance investigations of the dynamics of F centers in LiF
http://hdl.handle.net/2003/25356
Title: Magnetic resonance investigations of the dynamics of F centers in LiF
Authors: Suter, Dieter; Klempt, T.; Schweizer, S.; Schwartz, K.; Kanert, O.; Rogulis, U.; Spaeth, J.-M.2001-07-13T00:00:00ZDeconvolution and assignment of different optical transitions in the blue copper protein azurin from optically detected electron paramagnetic resonance spectroscopy
http://hdl.handle.net/2003/25355
Title: Deconvolution and assignment of different optical transitions in the blue copper protein azurin from optically detected electron paramagnetic resonance spectroscopy
Authors: Suter, Dieter; Börger, Birgit; Gutschank, Jörg; Bingham, Stephen J.; Thomson, Andrew J.
Abstract: Magnetic circular dichroism is a powerful spectroscopic tool for the assignment of optical resonance lines. An extension of this technique, microwave-modulated circular dichroism, provides additional details, in particular information about the orientation of optical transition moments. It arises from magnetization precessing around the static magnetic field, excited by a microwave field, in close analogy to electron paramagnetic resonance (EPR). In this paper we investigate the visible and near-infrared spectrum of the blue copper protein Pseudomonas aeruginosa azurin. Using a nonoriented sample (frozen solution), we apply this technique to measure the variation of the optical anisotropy with the wavelength. A comparison with the optical anisotropies of the possible ligand-field and charge-transfer transitions allows us to identify individual resonance lines in the strongly overlapping spectrum and assign them to specific electronic transitions. The technique is readily applicable to other proteins with transition metal centers.2001-02-15T00:00:00ZEffect of devitrification on the ionic diffusion of Li-disilicate
http://hdl.handle.net/2003/25354
Title: Effect of devitrification on the ionic diffusion of Li-disilicate
Authors: Suter, Dieter; Kanert, O.; Küchler, R.; Shannon, G. N.; Jain, H.2000-09-01T00:00:00ZFunctional Magnetic Resonance Imaging in Real-Time (FIRE)
http://hdl.handle.net/2003/25353
Title: Functional Magnetic Resonance Imaging in Real-Time (FIRE)
Authors: Suter, Dieter; Gembris, Daniel; Taylor, John G.; Schor, Stefan; Frings, Wolfgang; Posse, Stefan2000-02-01T00:00:00ZProbing the electronic structure of transition metal ion centres in proteins by coherent Raman detected electron paramagnetic resonance spectroscopy
http://hdl.handle.net/2003/25352
Title: Probing the electronic structure of transition metal ion centres in proteins by coherent Raman detected electron paramagnetic resonance spectroscopy
Authors: Suter, Dieter; Bingham, Stephen J.; Börger, Birgit; Thomson, Andrew J.; Gutschank, Jörg
Abstract: The simultaneous excitation of a paramagnetic sample with optical (laser) and microwave radiation can cause an amplitude or phase modulation of the transmitted light at the microwave frequency. The detection of this modulation indicates the presence of coupled optical and electron paramagnetic resonance (EPR) transitions in the sample. Here we report the first application of this technique to a biomolecule: the blue copper centre of Pseudomonas aeruginosa azurin. Using optical excitation at 686 nm, in the thiol to copper(II) charge transfer band, we measure a coherent Raman-detected EPR spectrum of a frozen aqueous solution. Its lineshape is characteristic of the magnetic circular dichroism along each principal g-value axis. This information allows electronic and structural models of transition metal ion centres in proteins to be tested.2000-02-01T00:00:00ZOptical detection of transition metal ion electron paramagnetic resonance by coherent Raman spectroscopy
http://hdl.handle.net/2003/25351
Title: Optical detection of transition metal ion electron paramagnetic resonance by coherent Raman spectroscopy
Authors: Suter, Dieter; Schweiger, Arthur; Bingham, Stephen J.; Thomson, Andrew J.1998-03-24T00:00:00ZOptically Enhanced Magnetic Resonance for the Study of Atom-Surface Interaction
http://hdl.handle.net/2003/25350
Title: Optically Enhanced Magnetic Resonance for the Study of Atom-Surface Interaction
Authors: Suter, Dieter; Grafström, Stefan
Abstract: We study surface-induced spin relaxation with a laser-assisted magnetic resonance experiment. Optical pumping with polarization-modulated light in a transverse magnetic field creates the spin polarization. For detection a probe laser beam is reflected at the surface and the change of its polarization is monitored. We present a comprehensive theoretical description, taking into account the spin relaxation at the surface, which leads to a spatially inhomogeneous magnetization near the surface as a result of the transient behavior of the atoms in this region. Analytical expressions are derived for the magnetic resonance signal, which show that the wall relaxation causes a clear modification of the line shape, characterized by pronounced wings. The experimental results obtained with bare and silicone-coated Pyrex-glass surfaces are well described by the theory. The bare glass surface causes strong relaxation, whereas the silicone-coated surface is only weakly depolarizing. The analysis of the magnetic-resonance line shape indicates that the depolarization probability per wall collision is ~0.01 in the latter case. The results are compared with corresponding results from the analysis of the optical resonance line measured with the same setup. Both types of measurements can be interpreted within the same theoretical framework and are fully consistent with one another.2004-02-19T00:00:00ZReflection Spectroscopy of Spin Polarized Atoms near a Dielectric Surface
http://hdl.handle.net/2003/25349
Title: Reflection Spectroscopy of Spin Polarized Atoms near a Dielectric Surface
Authors: Suter, Dieter; Grafström, Stefan; Blasberg, Tilo1993-01-01T00:00:00ZApplication of absorption measurements to the temperature determination of a cloud of cold Cesium atoms
http://hdl.handle.net/2003/25348
Title: Application of absorption measurements to the temperature determination of a cloud of cold Cesium atoms
Authors: Suter, Dieter; Marty, Thomas1995-01-01T00:00:00ZDetermination of Oscillator Strengths in Pr3+:YAlO3 by Raman Heterodyne and Hole Burning Spectroscopy
http://hdl.handle.net/2003/25347
Title: Determination of Oscillator Strengths in Pr3+:YAlO3 by Raman Heterodyne and Hole Burning Spectroscopy
Authors: Suter, Dieter; Blasberg, Tilo2000-04-06T00:00:00ZWall Relaxation of Spin Polarized Sodium Measured by Reflection Spectroscopy
http://hdl.handle.net/2003/25346
Title: Wall Relaxation of Spin Polarized Sodium Measured by Reflection Spectroscopy
Authors: Suter, Dieter; Grafström, Stefan1995-01-01T00:00:00ZDetermination of relative oscillator strengths by coherent Raman beats
http://hdl.handle.net/2003/25345
Title: Determination of relative oscillator strengths by coherent Raman beats
Authors: Suter, Dieter; Blasberg, Tilo1999-11-22T00:00:00ZExcitation of Coherent Raman Beats in Rare Earth Solids with a Bichromatic Laser Field.
http://hdl.handle.net/2003/25344
Title: Excitation of Coherent Raman Beats in Rare Earth Solids with a Bichromatic Laser Field.
Authors: Suter, Dieter; Blasberg, Tilo
Abstract: A new method is presented for measuring coherent Raman beats in systems with a wide spectral range that works even for weakly allowed optical resonance lines. A bichromatic pump laser field is used to resonantly pump a coherent excitation in the material, and a monochromatic test laser field, whose frequency coincides with that of one component of the pump laser beam.2002-10-03T00:00:00ZExperimental Observation of the Rotation Properties of Atomic Multipoles
http://hdl.handle.net/2003/25343
Title: Experimental Observation of the Rotation Properties of Atomic Multipoles
Authors: Suter, Dieter; Marty, Thomas1994-01-01T00:00:00ZNuclear Spin Relaxation of Pr3+ in YAlO3
http://hdl.handle.net/2003/25342
Title: Nuclear Spin Relaxation of Pr3+ in YAlO3
Authors: Suter, Dieter; Blasberg, Tilo
Abstract: The decay rates of the nuclear spin polarization of Pr^(3+) in a YAlO_3 matrix were measured in the temperature range 3-9 K by time-resolved spectral hole burning and simultaneous radio-frequency irradiation. In the low-temperature limit, diffusion of spin polarization to other regions of the inhomogeneously broadened optical line dominates the relaxation. At higher temperature, thermally activated multiple phonon processes become dominant.2002-01-10T00:00:00ZCoherent Raman Beats
http://hdl.handle.net/2003/25341
Title: Coherent Raman Beats
Authors: Suter, Dieter; Marty, Thomas1993-01-01T00:00:00ZLaser Induced Dynamics of Atomic Sublevel Coherences
http://hdl.handle.net/2003/25340
Title: Laser Induced Dynamics of Atomic Sublevel Coherences
Authors: Suter, Dieter; Marty, Thomas
Abstract: In atomic media, the interaction with resonant light leads to optical pumping and light shift effects which modify not only the static optical and magneto-optical properties of the media, but also the dynamics of multipole moments that are present in the electronic ground state as well as in electronically excited states. These modified dynamics include changes in precession frequencies and relaxation rates, but also laser-induced exchange of coherences between different atomic multipole moments. Using the Na ground state as an example, a theoretical analysis of these modified dynamics is presented, as well as experimental measurements of the laser induced coherence transfer.2002-08-19T00:00:00ZRotation Properties of Multipole Moments in Atomic Sublevel Spectroscopy
http://hdl.handle.net/2003/25339
Title: Rotation Properties of Multipole Moments in Atomic Sublevel Spectroscopy
Authors: Suter, Dieter; Marty, Thomas; Klepel, Harald1993-01-01T00:00:00ZQuantum Time Translation Machine
http://hdl.handle.net/2003/25338
Title: Quantum Time Translation Machine
Authors: Suter, Dieter; Ernst, Matthias; Ernst, Richard R.1993-01-01T00:00:00ZCoherent Effects in Laser Spectroscopy of Magnetic Multilevel Systems
http://hdl.handle.net/2003/25337
Title: Coherent Effects in Laser Spectroscopy of Magnetic Multilevel Systems
Authors: Suter, Dieter; Blasberg, Tilo; Klepel, Harald
Abstract: We present new experimental schemes for studying radiatively coupled atomic multilevel systems. These methods are aimed at creating order within the sublevel multiplets of complex multilevel systems and at extracting precise and detailed information about the order present in those systems. Time-resolved experiments provide not only static, but also dynamic information about these systems. Due to their heigh sensitivity and spatial selectivity, they may also be applied for magnetic resonance spectroscopy.1992-01-01T00:00:00ZIndirect Observation of 'Forbidden' Raman Transitions by Laser-Induced Coherence Transfer
http://hdl.handle.net/2003/25336
Title: Indirect Observation of 'Forbidden' Raman Transitions by Laser-Induced Coherence Transfer
Authors: Suter, Dieter; Klepel, Harald
Abstract: We demonstrate a new spectroscopic technique that makes it possible to obtain information from "forbidden" Raman transitions. The technique, which is based on time-resolved two-dimensional spectroscopy, uses laser-induced transfer of sublevel coherence from the Raman-inactive transition to an allowed Raman transition.1992-07-15T00:00:00ZTransverse Optical Pumping with Polarization-Modulated Light
http://hdl.handle.net/2003/25335
Title: Transverse Optical Pumping with Polarization-Modulated Light
Authors: Suter, Dieter; Klepel, Harald
Abstract: Optical pumping in a transverse magnetic field can be significantly enhanced if the polarization of the pump beam is modulated at a frequency near the Larmor frequency of the atomic system or a submultiple thereof. We give a theoretical analysis of the associated dynamics and present experimental results from the ground state of atomic sodium.2002-08-09T00:00:00ZEvanescent Wave Spectroscopy of Sublevel Resonances near a Glass/Vapor Interface
http://hdl.handle.net/2003/25334
Title: Evanescent Wave Spectroscopy of Sublevel Resonances near a Glass/Vapor Interface
Authors: Suter, Dieter; Äbersold, Jerome; Mlynek, Jürgen
Abstract: We report the observation of atomic sublevel coherence from a quasi-twodimensional region of atomic Na vapor near a glass surface. The ground state coherences are excited with a circularly polarized laser beam and detected with a linearly polarized probe beam that is incident on the interface under conditions of total interval reflection. The coherences of the atoms that are within the evanescent wave lead to selective absorption and phase shifts of the reflected beam which can be measured by a polarization-selective detection.2002-08-19T00:00:00ZLaser Excitation and Detection of Magnetic Resonance
http://hdl.handle.net/2003/25333
Title: Laser Excitation and Detection of Magnetic Resonance
Authors: Suter, Dieter; Mlynek, Jürgen1991-01-01T00:00:00ZPhase and Amplitude Variations of Optically Induced Spin Transients
http://hdl.handle.net/2003/25332
Title: Phase and Amplitude Variations of Optically Induced Spin Transients
Authors: Suter, Dieter; Rosatzin, Martin; Lange, Wulfhart; Mlynek, Jürgen1990-01-01T00:00:00ZOptically Induced Coherent Spin Transients in an Atomic Ground State
http://hdl.handle.net/2003/25331
Title: Optically Induced Coherent Spin Transients in an Atomic Ground State
Authors: Suter, Dieter; Mlynek, Jürgen; Rosatzin, Martin1990-01-01T00:00:00ZMonochloro- and dichloroacetic acids as carbon and energy sources for stable, methanogenic mixed culture
http://hdl.handle.net/2003/25330
Title: Monochloro- and dichloroacetic acids as carbon and energy sources for stable, methanogenic mixed culture
Authors: Suter, Dieter; Egli, Christine; Thüer, Markus; Cook, Alasdair M.; Leisinger, Thomas1989-04-20T00:00:00ZSuppression of the Zero Frequency Peak in Zero Field NMR
http://hdl.handle.net/2003/25329
Title: Suppression of the Zero Frequency Peak in Zero Field NMR
Authors: Suter, Dieter; Jarvie, T. P.; Takegoshi, K.; Pines, A.; Zax, D. R.
Abstract: In zero field NMR, a peak at zero frequency arising from nonevolving magnetization often obscures low-frequency lines. An indirect observation of second-rank order time evolution in zero field enables suppression of the zero frequency peak. This opens the possibility for resolution of previously marked low-frequency lines.2001-11-07T00:00:00ZExperimental classification of multi-spin coherence under the full rotation group
http://hdl.handle.net/2003/25328
Title: Experimental classification of multi-spin coherence under the full rotation group
Authors: Suter, Dieter; Pearson, J. G.
Abstract: The density operator of a coupled nuclear spin system often includes multi-spin coherences representing correlations between different spins. The generation and evolution of these coherences is governed by the dipole-dipole interactions between the spins and thus contains information about nuclear structure. Different multi-spin coherences may be distinguished by their behaviour under rotations. The maximum information extractable is determined by the irreducible representations of the full rotation group SO (3). By comparing the effect of rotation with various angles and rotation axes one can determine the expansion coefficients of the spin density operator in a basis of irreducible tensor operators. Experimentally, the rotation of the spins is achieved with rf pulses.2002-01-29T00:00:00ZBroadband Heteronuclear Spin Decoupling in Solids
http://hdl.handle.net/2003/25327
Title: Broadband Heteronuclear Spin Decoupling in Solids
Authors: Suter, Dieter; Pines, Alexander; Lee, J. H.; Drobny, G.
Abstract: Experimental results demonstrate that recently introduced COMARO decoupling sequences can be used for broadband heteronuclear decoupling in solids, providing decoupling performance that is considerably less sensitive to off-resonance effects than cw decoupling and allowing good decoupling with relatively low rf power.2001-01-29T00:00:00ZRecursive evaluation of interaction pictures
http://hdl.handle.net/2003/25326
Title: Recursive evaluation of interaction pictures
Authors: Suter, Dieter; Pines, Alexander2004-06-29T00:00:00ZBerry's phase in magnetic resonance
http://hdl.handle.net/2003/25325
Title: Berry's phase in magnetic resonance
Authors: Suter, Dieter; Chingas, Gerard C.; Pines, Alexander; Harris, Robert A.1987-01-01T00:00:00ZTheory of multiple pulse NMR at low and zero fields
http://hdl.handle.net/2003/25324
Title: Theory of multiple pulse NMR at low and zero fields
Authors: Suter, Dieter; Lee, C. J.; Pines, A.
Abstract: Coherent averaging with time-dependent magnetic fields at low and zero static magnetic fields encounters several features which are unfamiliar in high-field magnetic resonance. The principal differences are that magnetic field pulses act generally on all spin species in the sample and that the Hamiltonian contains additional terms that are normally discarded in a high static magnetic field. We illustrate how the full Hamiltonian or different terms of the Hamiltonian may be averaged to zero by sequences of 90° rotations around the x, y, and z axes. The two limiting cases of ideal delta-function pulses and windowless sequences are treated. We also show that the duality between rotations of space coordinates and spin coordinates allows one to replace spatial reorientations of the sample, such as magic-angle spinning, by time-dependent magnetic fields. Sequences of delta-function pulses at zero field are analogous to recursive expansion schemes of multiple-pulse sequences at high field. The terms of the full Hamiltonian appear also in the average Hamiltonian of high-field pulse sequences and can be manipulated by the same sequence of configurations as in zero-field multiple-pulse NMR.2004-06-29T00:00:00ZBroadband heteronuclear decoupling in the presence of homonuclear dipolar and quadrupolar interactions
http://hdl.handle.net/2003/25323
Title: Broadband heteronuclear decoupling in the presence of homonuclear dipolar and quadrupolar interactions
Authors: Suter, Dieter; Schenker, K. V.; Pines, A.
Abstract: A new family of composite decoupling sequences designed for heteronuclear broadband decoupling of spin-1 and spin-1/2 in solids and liquid crystals is introduced. The pulse sequences are windowless and perform net rotations in spin space about magic-angle axes. Computer simulations and experimental results are presented to demonstrate their decoupling performance and to discuss their susceptibility toward pulse imperfections. We describe the evaluation of the new sequences, called COMARO (composite magic-angle rotation), and point out some possibilities for further improvements.2004-07-13T00:00:00ZTheory of broadband heteronuclear decoupling in multispin systems
http://hdl.handle.net/2003/25322
Title: Theory of broadband heteronuclear decoupling in multispin systems
Authors: Suter, Dieter; Schenker, K. V.; Pines, A.
Abstract: The Waugh theory of broadband decoupling in NMR for I-S Spin 1/2 pairs is extended to arbitrary spin systems. It is shown that complete decoupling is achieved over a certain bandwidth if the irradiation scheme generates an average Hamiltonian for the I spins whose eigenvectors and eigenvalues are independent of resonance offset. If the observed S spins are only weakly coupled, it is possible to calculate the resulting spectrum directly from the offset dependence of the average Hamiltonian of the isolated I-spin system under the influence of the periodic decoupling sequence. The treatment applies to indirectly observed multiple-quantum transitions as well as to directly observable single-quantum resonance lines.2004-07-13T00:00:00ZMultiple quantum NMR excitation with a one-quantum Hamiltonian
http://hdl.handle.net/2003/25321
Title: Multiple quantum NMR excitation with a one-quantum Hamiltonian
Authors: Suter, Dieter; Liu, S. B.; Pines, A.
Abstract: Excitation of multiple quantum coherence in dipolar coupled spin systems is usually accomplished with a two-quantum multiple pulse sequence which can be time reversed by means of a 90° phase shift. The application of such an excitation scheme to a spin system in thermal equilibrium excites only even orders of multiple quantum coherence. We demonstrate here time reversible pulse sequences that excite all orders of coherence by creating a pure one-quantum average hamiltonian. We also describe pulse schemes which can be used to create pure one- or two-quantum average hamiltonians with variable scaling between +1 and −1. These excitation schemes are relevant to the study of spin clustering by multiple quantum NMR.2001-11-16T00:00:00ZRadiofrequency-pulse excitation in time-domain zero field magnetic resonance
http://hdl.handle.net/2003/25320
Title: Radiofrequency-pulse excitation in time-domain zero field magnetic resonance
Authors: Suter, Dieter; Kreis, R.; Ernst, R. R.
Abstract: Time-domain zero-field magnetic resonance is extended by applying radiofrequency pulses for the initiation and termination of precession at zero field. Radiofrequency-pulse excitation is suitable for observing resonance in wide quadrupolar spectra and for the design of more elaborate pulse experiments.2001-11-21T00:00:00ZTime-domain zero field magnetic resonance with field pulse excitation
http://hdl.handle.net/2003/25319
Title: Time-domain zero field magnetic resonance with field pulse excitation
Authors: Suter, Dieter; Kreis, R.; Ernst, R. R.
Abstract: An improved technique of time-domain zero-field magnetic resonance is proposed which employs a pair of short magnetic field pulses for excitation and detection of free precession.2001-11-28T00:00:00ZTwo-dimensional chemical exchange and cross-relaxation spectroscopy of coupled nuclear spins
http://hdl.handle.net/2003/25318
Title: Two-dimensional chemical exchange and cross-relaxation spectroscopy of coupled nuclear spins
Authors: Suter, Dieter; Macura, S.; Huang, Y.; Ernst, R. R.
Abstract: The features of two-dimensional cross-relaxation and chemical exchange spectroscopy of coupled spins are investigated theoretically and by experiment. It is shown that spin-spin couplings can lead to J cross-peaks in analogy to cross-peaks in two-dimensional autocorrelated spectroscopy. They reflect a coherent magnetization transfer in contrast to the incoherent processes responsible for cross-relaxation and for chemical exchange. Possibilities of selectively suppressing J cross-peaks are discussed.2004-07-12T00:00:00ZSpins as qubits
http://hdl.handle.net/2003/25028
Title: Spins as qubits
Authors: Suter, Dieter; Mahesh, T. S.
Abstract: Storing information in quantum mechanical degrees of freedom and processing it by unitary transformation promises a new class of computers that can efficiently solve problems for which no efficient classical algorithms are known. The most straightforward implementation of this type of information processing uses nuclear spins to store the information and nuclear magnetic resonance for processing it. We discuss the basics of quantum information processing by NMR, with an emphasis on two fields of research: the design and implementation of robust logical gate operations and the loss of quantum information, which is known as decoherence.2008-02-05T00:00:00ZEffect of cholesterol on diffusion in surfactant bilayers
http://hdl.handle.net/2003/25027
Title: Effect of cholesterol on diffusion in surfactant bilayers
Authors: Suter, Dieter; Pieper, Thorsten; Markova, Svetlana; Kinjo, Masataka
Abstract: Biological membranes consist of lipid bilayers with liquid-ordered and liquid-disordered phases. It is believed that cholesterol controls the size of the microdomains in the liquid-ordered phase and thereby affects the mobility as well as the permeability of the membrane. We study this process in a model system consisting of the nonionic surfactant C12E5 and water in the lamellar phase. We measure the diffusion of fluorescent probe molecules (rhodamine B) by fluorescence correlation spectroscopy. For different surfactant to water ratios, we measure how the molecular mobility varies with the amount of cholesterol added. We find that a reduction of the diffusion coefficient is already detectable at a molar ratio of 8 mol % cholesterol.2007-10-29T00:00:00ZEffect of different sodium halides on the self-association of tertiary butanol in water
http://hdl.handle.net/2003/25026
Title: Effect of different sodium halides on the self-association of tertiary butanol in water
Authors: Suter, Dieter; Jeufack, Hervé Momo
Abstract: The molecular self-association of hydrophobic substances is an important process for many biological systems. Here, the authors study the effect of salt on the molecular self-association of t-butanol in water solution, using NMR techniques. They compare the effects of different sodium halides (NaCl, NaBr, and NaI) as a function of their concentration.2007-04-10T00:00:00ZMagnetic and optical anisotropy of Clostridium pasteurianum rubredoxin from optically detected electron paramagnetic resonance
http://hdl.handle.net/2003/25025
Title: Magnetic and optical anisotropy of Clostridium pasteurianum rubredoxin from optically detected electron paramagnetic resonance
Authors: Suter, Dieter; Börger, Birgit
Abstract: The high-spin Fe(III)-center of oxidized rubredoxin from Clostridium pasteurianum shows a complicated, temperature-dependent EPR spectrum. We combine conventional EPR spectroscopy with optically detected EPR (ODEPR) to elucidate the electronic structure of this protein metal center. The ODEPR experiment, which can be considered as coherent Raman scattering or modulated magnetic circular dichroism (MCD), yields spectra that depend on the relative orientation of optical and magnetic dipole moments. A detailed analysis of the spectra shows that they correspond to a zero-field splitting of D = +46.3 GHz and a strong rhombic distortion with E/D = 0.25. In the frozen solution, conformational strain gives rise to variation of the rhombicity, which can be measured quantitatively from the EPR line shape. Analysis of the ODEPR line shapes yields the orientation of the optical anisotropy with respect to the magnetic g-tensor. We compare the results from this study to published results on EPR, optical spectroscopy, and MCD.2001-12-01T00:00:00ZMagnetic circular dichroism anisotropy from coherent Raman detected electron paramagnetic resonance spectroscopy
http://hdl.handle.net/2003/25024
Title: Magnetic circular dichroism anisotropy from coherent Raman detected electron paramagnetic resonance spectroscopy
Authors: Suter, Dieter; Bingham, Stephen J.; Gutschank, Jörg; Börger, Birgit; Thomson, Andrew J.
Abstract: Measurement of magnetic circular dichroism (MCD) anisotropy has contributed greatly to the understanding of the electronic structure of transition metal ion centers in both biological and nonbiological materials. Compared to previous methods, optically detected electron paramagnetic resonance experiments can measure MCD anisotropy with dramatically improved orientational resolution. In this paper the relevant theory for systems with an isolated Kramers doublet ground level is derived and its application illustrated using a transition metal ion center in a protein: low spin ferric haem.2000-09-08T00:00:00ZDepth profile of the implantation-enhanced intermixing of Ga + focused ion beam in AlAs/GaAs quantum wells
http://hdl.handle.net/2003/25023
Title: Depth profile of the implantation-enhanced intermixing of Ga + focused ion beam in AlAs/GaAs quantum wells
Authors: Suter, Dieter; Eshlaghi, Soheyla; Meier, Cedrik; Reuter, D.; Wieck, A. D.
Abstract: The implantation-induced intermixing depth profile for 100 keV Ga + ions was determined by photoluminescence measurements on a series of samples containing quantum wells at variable depth from the surface but identical thickness. They were uniformly implanted and subsequently a rapid thermal annealing was applied. The measured maximum of the intermixing occurred at a depth of about 70 nm, significantly deeper than theoretical predictions. These results are important for achieving sufficient intermixing with a low implantation dose, thereby optimizing crystal quality and lateral resolution.1999-12-01T00:00:00ZOptically detected electron paramagnetic resonance by microwave modulated magnetic circular dichroism
http://hdl.handle.net/2003/25022
Title: Optically detected electron paramagnetic resonance by microwave modulated magnetic circular dichroism
Authors: Suter, Dieter; Börger, Birgit; Bingham, Stephen J.; Gutschank, Jörg; Schweika, Marc-Oliver; Thomson, Andrew J.
Abstract: Electron paramagnetic resonance (EPR) can be detected optically, with a laser beam propagating perpendicular to the static magnetic field. As in conventional EPR, excitation uses a resonant microwave field. The detection process can be interpreted as coherent Raman scattering or as a modulation of the laser beam by the circular dichroism of the sample oscillating at the microwave frequency. The latter model suggests that the signal should show the same dependence on the optical wavelength as the MCD signal. We check this for two different samples [cytochrome c-551, a metalloprotein, and ruby (Cr3 + :Al2O3)]. In both cases, the observed wavelength dependence is almost identical to that of the MCD signal. A quantitative estimate of the amplitude of the optically detected EPR signal from the MCD also shows good agreement with the experimental results.1999-11-08T00:00:00ZBreaking the Stokes-anti-Stokes symmetry in Raman heterodyne detection of magnetic resonance transitions
http://hdl.handle.net/2003/25021
Title: Breaking the Stokes-anti-Stokes symmetry in Raman heterodyne detection of magnetic resonance transitions
Authors: Suter, Dieter; Neuhaus, Rudolf; Sellars, Matthew J.; Bingham, Stephen J.
Abstract: Coherent Raman scattering can generate Stokes and anti-Stokes fields of comparable intensities. When the Raman shift is due to a magnetic resonance transition (usually in the MHz to GHz range), the Raman fields are generally detected by optical heterodyne detection, using the excitation laser as the local oscillator. In this case, the two sidebands generate beat signals at the same frequency and are therefore indistinguishable. Separation of the two contributions becomes possible, however, by superheterodyne detection with a frequency-shifted optical local oscillator. We compare the two scattering processes, and show how the symmetry between them can be broken in Pr3+:YAlO3.1998-12-01T00:00:00Zac Stark effect in a doubly driven three-level atom
http://hdl.handle.net/2003/25020
Title: ac Stark effect in a doubly driven three-level atom
Authors: Suter, Dieter; Wei, Changjiang; Windsor, Andrew S. M.; Manson, Neil B.
Abstract: In this paper we present a detailed treatment of the ac Stark effect of a three-level atom driven by two strong laser fields in a cascade scheme. We consider two situations where there is a weak laser field probing a new transition starting from one of the three levels to a fourth level. In one case the initial level of the probed transition is the ground state and in the other case the initial level is the intermediate state. For both situations we derive an analytical expression for the absorptive and dispersive responses of the weak probe field and present the spectrum obtained from numerical calculation. The general feature of the spectrum has a three-peak structure. The positions and relative intensities of the three spectral components are affected strongly by the driving field intensities and detunings. An account of the spectrum is given in terms of the dressed-state formalism.1998-09-01T00:00:00Z