Dittrich, ThomasKetzmerick, RolandOtto, Marc-FelixSchanz, Holger2004-12-032004-12-0320012001http://hdl.handle.net/2003/77110.17877/DE290R-10640enThe American Physical SocietyPhysical Review Letters530Classical and Quantum Hamiltonian Ratchets10.1103/PhysRevLett.87.070601article (journal)