ROLE OF DECOHERENCE ON ADIABATIC QUANTUM MOTORS.

RAUL BUSTOS MARUN; LUCAS FERNÁNDEZ-ALCÁZAR; HORACIO M. PASTAWSKI

Buenos Aires

Congreso; 27th International conference on low physics; 2014

In recent years, several authors have explored the idea of quantum machines [PRL 79, 10 (1997); PRL 96, 130602 (2006); PRL 111, 060802 (2013)]. However, the true role of quantum mechanics on this type of devices is sometimes blurry. In this work we study the role of decoherence on a particular example of quantum machines: adiabatic quantum motors [PRL 111, 060802 (2013)]. The working principle of this type of motors relies on reverse quantum pumping and consequently it isexpected a strong effect, on the properties of the systems, of the degree of coherence of the electrons that go through it. We study two different type of systems: a quantum-dot based motor and a reverse-Thouless-pumpmotor. The effect of decoherence was modeled through the fictitious probes technique [PRB 33, 3020 (1986); PRB 41, 7411 (1990)]. In the case of the reverse-Thouless-pump motor we use a tight binding Hamiltonian to model the system, which allow us, on one hand, to include the effect ofdecoherence in a more realistic way and, on the other, to analyze the deviations from the approximations used in previous works [PRL 111, 060802 (2013)]. On both examples we study the effect of decoherence on the maximum work performed per cycle, the friction coefficient, and theefficiency of the motor.