Quantum dephasing induced by non-Markovian random telegraph noise

TL;DR

This paper provides an exact theoretical analysis of quantum dephasing caused by non-Markovian random telegraph noise, revealing how environmental memory effects influence quantum coherence and can be modulated externally.

Contribution

It introduces an exact expression for the dephasing factor in non-Markovian environments and discusses how environmental memory kernels affect quantum dephasing dynamics.

Findings

Dephasing dynamics depend on environmental memory and system-environment interaction.

Non-Markovian character in dephasing is not always present despite non-Markovian noise.

External modulation frequency can control quantum dephasing.

Abstract

We theoretically study the dynamical dephasing of a quantum two level system interacting with an environment exhibiting non-Markovian random telegraph fluctuations. The time evolution of the conditional probability of the environmental noise is governed by a generalized master equation depending on the environmental memory effect. The expression of the dephasing factor is derived exactly which is closely associated with the memory kernel in the generalized master equation for the conditional probability of the environmental noise. In terms of three important types memory kernels, we discuss the quantum dephasing dynamics of the system and the non-Markovian character exhibiting in the dynamical dephasing induced by non-Markovian random telegraph noise. We show that the dynamical dephasing of the quantum system does not always exhibit non-Markovian character which results from that the non-Markovian character in the dephasing dynamics depends both on the environmental non-Markovian character and the interaction between the system and environment. In addition, the dynamical dephasing of the quantum system can be modulated by the external modulation frequency of the environment. This result is significant to quantum information processing and helpful for further understanding non-Markovian dynamics of open quantum systems.