Decoherence of adiabatically steered quantum systems

TL;DR

This paper investigates how Markovian environmental noise influences the adiabatic evolution of a two-level quantum system, revealing robustness of ground state pumping against noise and emphasizing the importance of including non-secular terms in the master equation.

Contribution

It provides a comprehensive analysis of the master equation for adiabatically driven quantum systems under Markovian noise, highlighting the physical implications and control strategies for environmental effects.

Findings

Zero-temperature environment does not affect ground state evolution in the adiabatic limit.

Environmental relaxation helps prevent error accumulation in quantum pumping.

Neglecting non-secular terms leads to unphysical results like charge non-conservation.

Abstract

We study the effect of Markovian environmental noise on the dynamics of a two-level quantum system which is steered adiabatically by an external driving field. We express the master equation taking consistently into account all the contributions to the lowest non-vanishing order in the coupling to the Markovian environment. We study the master equation numerically and analytically and we find that, in the adiabatic limit, a zero-temperature environment does not affect the ground state evolution. As a physical application, we discuss extensively how the environment affects Cooper pair pumping. The adiabatic ground state pumping appears to be robust against environmental noise. In fact, the relaxation due to the environment is required to avoid the accumulation of small errors from each pumping cycle. We show that neglecting the non-secular terms in the master equation leads to unphysical results, such as charge non-conservation. We discuss also a possible way to control the environmental noise in a realistic physical setup and its influence on the pumping process.