Manipulating decoherence: Towards a universal framework

TL;DR

This paper introduces a unified, time-dependent framework to manipulate decoherence and entanglement sudden death in quantum photonic systems, enabling control over quantum entanglement degradation.

Contribution

It develops a broad, formal approach using a time-dependent formalism to control decoherence effects, including entanglement sudden death, in quantum channels.

Findings

Time-delay parameter can tune entanglement sudden death.

A novel setup explores amplitude-damping and correlated channels.

Generalized Kraus operators treat different decoherence regimes.

Abstract

Coherence is a fundamental characteristic of quantum systems and central to understanding quantum behaviour. It is also important for a variety of applications in quantum information. However, physical systems suffer from decoherence due to their interaction with the environment. Although different approaches have been developed to deal with decoherence, there is no unified framework to manipulate the degradation of quantum entanglement. In this work, using a time-dependent formalism (TDF), we take a step towards a broad framework for manipulating decoherence in photonic systems that lead to {\it Entanglement Sudden Death} (ESD). We show explicitly that a time-delay parameter can be used to tune ESD in damping channels. We further propose a novel setup along with the TDF to explore between two limits, one of an amplitude-damping channel (ADC) and another of a correlated amplitude-damping channel (CADC). The generalized definition of the Kraus operators in the TDF allows treatment of the three domains where ESD is hastened, delayed, or completely avoided. We show how a cascade of such damping channels is affected by to the time-delay parameter.