Effect of bath temperature on the decoherence of quantum dissipative systems

Abstract

We report an anomalous decoherence phenomenon of a quantum dissipative system in the framework of a stochastic decoupling scheme along with a hierarchical equations-of-motion formalism without the usual Born-Markov or weak coupling approximations. It is found that the decoherence of a two-qubit spin-boson model can be reduced by increasing the bath temperature in strongcoupling regimes. For the weak-coupling situation, we find that the bath temperature may enhance the decoherence. This result is contrary to the common recognition that a higher bath temperature always induces a more severe decoherence and suggests that a decoherence dynamical transition occurs in this two-qubit spin-boson model. We also demonstrate that the critical transition point can be characterized by the behavior of the frequency spectrum of the quantum coherence indicator.

Quantum parameter estimation in a dissipative environment

“…Thus, the HEOM can be viewed as an exactly numerical treatment of the quantum dissipative dynamics. In recent years, the HEOM approach has been successfully used to study the anomalous decoherence phenomenon in a nonlinear spin-boson model [51], the quantum Zeno and anti-Zeno phenomena in a noisy environment [52], as well as the influence of counter-rotating-wave terms on the measure of non-Markovianity [53].…”

Quantum Zeno and anti-Zeno effects in quantum dissipative systems

“…One commonly believed concept is that the bath temperature can speed up the destruction of quantum coherence. However, some studies have shown that the bath temperature is able to reduce the decoherence in some quantum dissipative systems [26,27]. This result is contrary to the common recognition that a higher bath temperature always induces a more severe decoherence and suggests that the bath temperature plays a very intricate role in quantum dissipative systems.…”

“…17 reduces to the hierarchical equations in Ref. [27]. This approximation is reliable when the bath temperature is not very low.…”

“…with X× Ŷ ≡ [ X, Ŷ ] = X Ŷ − Ŷ X and X• Ŷ ≡ { X, Ŷ } = X Ŷ + Ŷ X. The same hierarchical equations can be also derived by making use of the stochastic decoupling scheme proposed by Shao et al [27].…”

Realization of hierarchical equations of motion from stochastic perspectives

“…with χ stands for the coupling strength between the quantum subsystem and the bath, parameter ω c is the cutoff frequency. In this case, the bath correlation function ξ(t) is given by [40,[63][64][65]…”