title: Quantum dissipative Rashba spin ratchets.
abstract: We predict the possibility to generate a finite stationary spin current by applying an unbiased ac driving to a quasi-one-dimensional asymmetric periodic structure with Rashba spin-orbit interaction and strong dissipation. We show that under a finite coupling strength between the orbital degrees of freedom the electron dynamics at low temperatures exhibits a pure spin ratchet behavior, i.e., a finite spin current and the absence of charge transport in spatially asymmetric structures. It is also found that the equilibrium spin currents are not destroyed by the presence of strong dissipation.
authors.affiliation: Institut für Theoretische Physik, Universität Regensburg, Regensburg, Germany.
authors.forename: Sergey
authors.initials: S
authors.lastname: Smirnov
authors.forename: Dario
authors.initials: D
authors.lastname: Bercioux
authors.forename: Milena
authors.initials: M
authors.lastname: Grifoni
authors.forename: Klaus
authors.initials: K
authors.lastname: Richter