Manipulating sudden death of entanglement of two-qubit X-states in thermal reservoirs

TL;DR

This paper investigates how the sudden death of entanglement in two-qubit X-states interacting with thermal reservoirs can be controlled, revealing that at finite temperatures all such states experience entanglement sudden death.

Contribution

It derives a necessary and sufficient criterion for entanglement sudden death in two-qubit X-states interacting with thermal reservoirs and explores how to manipulate its timing.

Findings

At finite temperature, all initial X-states exhibit entanglement sudden death.

A simple criterion for ESD based on the Peres-Horodecki criterion is established.

Conditions for hastening, delaying, or avoiding ESD are identified.

Abstract

Manipulation of sudden death of entanglement (ESD) of two qubits interacting with statistically uncorrelated thermal reservoirs is investigated. It is shown that for initially prepared X-states of the two qubits a simple (necessary and sufficient) criterion for ESD can be derived with the help of the Peres-Horodecki criterion. This criterion implies that, in contrast to the zero-temperature case, at finite temperature of at least one of the reservoirs all initially prepared two-qubit X-states exhibit ESD. General conditions are derived under which ESD can be hastened, delayed, or averted.