Universality of Sudden Death of Entanglement

TL;DR

This paper demonstrates that the sudden death of entanglement is a universal phenomenon for two non-interacting qubits coupled to independent Markovian environments, showing it occurs in almost all realistic dynamical models.

Contribution

The paper provides a rigorous proof that the sudden death of entanglement is nearly always present in such quantum systems, establishing its universality.

Findings

Sudden death of entanglement occurs in almost all models.

Models without sudden death are highly idealized and rare.

Conditions for entanglement sudden death are generally satisfied.

Abstract

We present a constructive argument to demonstrate the universality of the sudden death of entanglement in the case of two non-interacting qubits, each of which generically coupled to independent Markovian environments at zero temperature. Conditions for the occurrence of the abrupt disappearance of entanglement are determined and, most importantly, rigorously shown to be almost always satisfied: Dynamical models for which the sudden death of entanglement does not occur are seen to form a highly idealized zero-measure subset within the set of all possible quantum dynamics.