Remanent quantum correlations in dissipative qubits

Abstract

Starting from the exact evolution of a Markovian dissipative quantum walk, a non-Markovian decoherence of two qubits interacting with a phonon thermal bath has been investigated analytically using quantum information tools. Concurrence and quantum discord are affected in a complex way, showing that entanglement decreases with dissipation. At the limit where dissipation dominates, quantum correlations survive in time as $propto t^{-1/2}.$ Thus, even under the influence of dissipation two qubits retain their quantumness for a long time. Quantum correlations could be therefore observed for a long time in related photonic experiments.