Quantum dephasing dynamics in the presence of asymmetric random telegraph noise

Random telegraph noise (RTN) has been widely used to describe the environmental effects on open quantum systems. In most cases, it is assumed that the environmental noise described by RTN has symmetric properties. However, in some important physical processes, the asymmetric characteristics of environmental noise play a crucial role in the dynamical evolution of the quantum systems. We theoretically study the dephasing dynamics of a two-level quantum system induced by RTN with asymmetric properties. Within the framework of the stochastic Liouville equation, we derive the exact expression of the decoherence function quantifying the coherence evolution of the quantum system. It is shown that, in contrast to the case of the symmetric RTN, the asymmetric RTN can induce a frequency shift and may lead to non-Markovian behavior in the decoherence dynamics of the quantum system. Furthermore, by adjusting the average transition rate, the transition rate difference, and the transition amplitude difference of the environmental noise, the decoherence dynamics of the quantum system can be effectively modulated.