Initial Conditions and Entanglement Sudden Death

TL;DR

This paper investigates entanglement sudden death (ESD), revealing how initial conditions influence its occurrence and providing rules to manage ESD based on purity, entanglement, and excitation without needing phase control.

Contribution

It introduces simple rules to predict and control ESD timing for Bell states using only three initial parameters, without requiring phase information.

Findings

ESD can occur while local coherences remain non-zero.

Rules restrict ESD occurrence based on initial purity, entanglement, and excitation.

Management tools for ESD depend on three initial parameters.

Abstract

We report results bearing on the behavior of non-local decoherence and its potential for being managed or even controlled. The decoherence process known as entanglement sudden death (ESD) can drive prepared entanglement to zero at the same time that local coherences and fidelity remain non-zero. For a generic ESD-susceptible Bell superposition state, we provide rules restricting the occurrence and timing of ESD, amounting to management tools over a continuous variation of initial conditions. These depend on only three parameters: initial purity, entanglement and excitation. Knowledge or control of initial phases is not needed.