Demon-free quantum Brownian motors

Abstract

A quantum Smoluchowski equation is put forward that consistently describes thermal quantum states. In particular, it notably does not induce a violation of the second law of thermodynamics. This so modified kinetic equation is applied to study {\it analytically} directed quantum transport at strong friction in arbitrarily shaped ratchet potentials that are driven by nonthermal two-state noise. Depending on the mutual interplay of quantum tunneling and quantum reflection these quantum corrections can induce both, either a sizable enhancement or a suppression of transport. Moreover, the threshold for current reversals becomes markedly shifted due to such quantum fluctuations.

4 pages 3 figures

References in corpus (2)

• Quantum ratchet effect for vortices
• Rectification of laser-induced electronic transport through molecules

Cited by in corpus (8)

• Artificial Brownian motors: Controlling transport on the nanoscale
• Fundamental Aspects of Quantum Brownian Motion
• Fluctuation theorems in driven open quantum systems
• Caldeira--Leggett quantum master equation in Wigner phase space: continued-fraction solution and application to Brownian motion in periodic potentials
• Dynamics of the quantum Duffing oscillator in the driving induced bistable regime
• Quantum Smoluchowski equation for driven systems
• Underdamped quantum ratchets
• Magnetic flux in mesoscopic rings: Quantum Smoluchowski regime