Authors: | Stolze, Joachim Valentí, Roser Hirschfeld, Peter J. |
Title: | Lower Bounds for the Ground-State Energies of the 2D Hubbard and t-J Models |
Language (ISO): | en |
Abstract: | We present simple lower bounds on the ground-state energy of the two-dimensional (2D) Hubbard and t-J models for arbitrary values of band filling and coupling constant. For the Hubbard model we derive two types of bounds, both based on decomposing the model Hamiltonian into a sum of sub-Hamiltonians. For a decomposition into local cluster sub-Hamiltonians, we perform a generalized Legendre transform on previously derived bounds for the grand-canonical potential. For a decomposition into spin-up and spin-down parts, previous results on the spinless Falicov-Kimball model may be used to obtain bounds for the Hubbard model, generalizing a result of Langer and Mattis to arbitrary filling. For the 2D t-J model we have only considered the decomposition into clusters. The 1D Hubbard model is used as a test case. The bounds may be improved by diagonalizing the Hamiltonian for larger clusters. |
URI: | http://hdl.handle.net/2003/25427 http://dx.doi.org/10.17877/DE290R-3489 |
Publishers Link: | http://t1.physik.tu-dortmund.de/stolze/publications/PRB_43_13743.pdf |
Issue Date: | 1991 |
Provenance: | The American Physical Society |
URL: | http://dx.doi.org/ 10.1103/PhysRevB.43.13743 |
Citation: | Valenti, Roser; Stolze, Joachim; Hirschfeld, Peter J.: Lower Bounds for the Ground-State Energies of the 2D Hubbard and t-J Models. In: Physical Review B Nr. 16, Jg. 43(1991), S. 13743-13746, doi: 10.1103/PhysRevB.43.13743 . |
Appears in Collections: | Stolze, Joachim Prof. Dr. |
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