Disentanglement Dynamics in Nonequilibrium Environments

Abstract

We theoretically study the non-Markovian disentanglement dynamics of a two-qubit system coupled to nonequilibrium environments with nonstationary and non-Markovian random telegraph noise statistical properties. The reduced density matrix of the two-qubit system can be expressed as the Kraus representation in terms of the tensor products of the single qubit Kraus operators. We derive the relation between the entanglement and nonlocality of the two-qubit system which are both closely associated with the decoherence function. We identify the threshold values of the decoherence function to ensure the existences of the concurrence and nonlocal quantum correlations for an arbitrary evolution time when the two-qubit system is initially prepared in the composite Bell states and the Werner states, respectively. It is shown that the environmental nonequilibrium feature can suppress the disentanglement dynamics and reduce the entanglement revivals in non-Markovian dynamics regime. In addition, the environmental nonequilibrium feature can enhance the nonlocality of the two-qubit system. Moreover, the entanglement sudden death and rebirth phenomena and the transition between quantum and classical nonlocalities closely depend on the parameters of the initial states and the environmental parameters in nonequilibrium environments.

Dephasing Dynamics in a Non-Equilibrium Fluctuating Environment

“…The non-Markovian statistics of the generalized RTN is characterized by the master equations for the multi-time probability distributions [ 60 ]: with being the memory kernel of the generalized RTN and the multi-time probability and the matrix for transition respectively written as The statistical property of the environmental noise depends on its prior history because of the fact that the memory effect has been taken into consideration. The non-stationary environmental statistical property of the generalized RTN arises from the single-point probability distribution [ 77 ]: where a is the non-stationary parameter with and denotes the auxiliary function with and representing the inverse Laplace transform. For the memoryless case, namely , then the generalized RTN returns to the Markovian one.…”

“…The statistical property of the environmental noise depends on its prior history because of the fact that the memory effect has been taken into consideration. The non-stationary environmental statistical property of the generalized RTN arises from the single-point probability distribution [77]:…”

Nonequilibrium Effects on the Precision of Parameter Estimation

“…These nonequilibrium features play a critical role in decoherence, [62,63] quantum speed limits, [64] and the geometric phase of quantum systems. [65] Researchers have also explored quantum correlation dynamics in the nonequilibrium environment, [66][67][68][69][70] including control of double-sudden transitions for one-norm geometric quantum discord [66] and postponement of sudden transitions for quantum discord. [67] All these results show that nonequilibrium effects significantly influence quantum resources interconnected with QFI.…”

Entanglement Dynamics Governed by Time-Dependent Quantum Generators

“…The analysis of bipartite entanglement may involve two qubits embedded in a common environment [35] or two independent baths [36]. One specific example involves a nonequilibrium environment [37][38][39], where one can observe non-Markovian effects that bring an increase in the amount of entanglement due to information backflows [40]. In addition, the problem of transferring quantum systems through spin chain systems have been discussed in the context of non-Markovianity [41].…”