Decoherence-free dynamics of quantum discord for two correlated qubits in finite-temperature reservoirs

TL;DR

This paper explores how quantum discord between two correlated qubits can remain unaffected by decoherence in finite-temperature reservoirs, and how to control and extend this decoherence-free evolution through system parameters.

Contribution

It provides an exact model demonstrating the influence of reservoir temperature on quantum discord's decoherence-free evolution and methods to prolong it by parameter tuning.

Findings

Reservoir temperature significantly impacts DFE of quantum discord.

Suitable parameter choices can control and extend DFE time.

Exact solvable model confirms the possibility of decoherence-free quantum discord dynamics.

Abstract

We investigate decoherence-free evolution (DFE) of quantum discord (QD) for two initially-correlated qubits in two finite-temperature reservoirs using an exactly solvable model. We study QD dynamics of the two qubits coupled to two independent Ohmic reservoirs when the two qubits are initially prepared in X-type quantum states. It is found that reservoir temperature significantly affects the DFE dynamics. We show that it is possible to control the DFE and to prolong the DFE time by choosing suitable parameters of the two-qubit system and reservoirs.