Non-adiabatic effect in quantum pumping for a spin-boson system

TL;DR

This paper investigates how non-adiabatic effects influence quantum pumping in a spin-boson system, revealing dependence on initial conditions and deriving an analytical expression for the non-adiabatic contribution to the current.

Contribution

It provides the first analytical expression for non-adiabatic effects in quantum pumping and extends the steady heat fluctuation theorem to modulated temperature scenarios.

Findings

Pumping current depends on initial conditions under sinusoidal temperature control.

Non-adiabatic effects contribute proportionally to ^3 in the current.

Analytical results are confirmed by numerical calculations.

Abstract

We clarify the role of non-adiabatic effects in a quantum pumping for a spin-boson system. When we sinusoidally control the temperatures of two reservoirs with \pi/2 phase difference, we find that the pumping current strongly depends on the initial condition, and thus, the current deviates from that predicted by the adiabatic treatment. We also analytically obtain the contribution of non-adiabatic effects in the pumping current proportional to \Omega^3 where \Omega is the angular frequency of the temperature control. The validity of the analytic expression is verified by our numerical calculation. Moreover, we extend the steady heat fluctuation theorem to the case for slowly modulated temperatures and large transferred energies.