Quantum Ratchets

Zusammenfassung

We investigate quantum Brownian motion in adiabatically rocked ratchet systems. Above a crossover temperature Tc tunneling events are rare, yet they already substantially enhance the classical particle current. Below Tc, quantum tunneling prevails and the classical predictions grossly underestimate the transport. Upon approaching T=0 the quantum current exhibits a tunneling induced reversal, and tends to a finite limit.