Decoherence in current induced forces: Application to adiabatic quantum motors

LUCAS FERNÁNDEZ-ALCÁZAR; RAÚL A. BUSTOS-MARÚN; HORACIO M. PASTAWSKI

PHYSICAL REVIEW B

AMER PHYSICAL SOC

Lugar: New York; Año: 2015 vol. 92 p. 75406 - 75406

1098-0121

Current induced forces are not only related with the discrete nature of electrons but also with its quantum character. It is natural then to wonder about the effect of decoherence. Here, we develop the theory of current induced forces including dephasing processes and we apply it to study adiabatic quantum motors (AQMs). The theory is based on Büttiker?s fictitious probe model which here is reformulated for this particular case. We prove that it accomplishes fluctuation-dissipation theorem. We also show that, in spite of decoherence, the total work performed by the current induced forces remains equal to the pumped charge per cycle times the voltage. We find that decoherence provides new mechanisms that correct not only the current induced forces of the system but also its intrinsic friction and noise, affecting in a non trivial way the efficiency of AQMs. We apply the theory to study an AQM inspired by a classical peristaltic pump where we surprisingly find that decoherence can play a crucial role by triggering its operation. Our results can help to understand how environmentally induced dephasing affects the quantum behavior of nano-mechanical devices.