Entanglement Sudden Death in Band Gaps

TL;DR

This paper investigates how structured environments with spectral gaps influence entanglement dynamics between two qubits, revealing methods to control and prevent entanglement sudden death through environment engineering.

Contribution

It provides an exact evaluation of time-dependent entanglement in non-Markovian environments using the pseudomode method, highlighting control strategies for entanglement preservation.

Findings

Entanglement trapping occurs in environments with a two-pole spectral gap.

Modifying qubit-pseudomode detuning can control entanglement sudden death.

Prevention of entanglement sudden death is possible in weak-coupling regimes.

Abstract

Using the pseudomode method, we evaluate exactly time-dependent entanglement for two independent qubits, each coupled to a non-Markovian structured environment. Our results suggest a possible way to control entanglement sudden death by modifying the qubit-pseudomode detuning and the spectrum of the reservoirs. Particularly, in environments structured by a model of a density-of-states gap which has two poles, entanglement trapping and prevention of entanglement sudden death occur in the weak-coupling regime.