Local generation of entanglement with Redfield dynamics

TL;DR

This paper investigates the use of Redfield dynamics in open quantum systems, revealing that it can unphysically generate entanglement locally, which challenges its physical consistency and applicability.

Contribution

The study demonstrates that Redfield dynamics can produce entanglement through local actions, highlighting a fundamental inconsistency in its physical interpretation.

Findings

Redfield dynamics can generate entanglement locally.

Unphysical entanglement persists for finite times.

Redfield dynamics may violate physical constraints in open systems.

Abstract

In phenomenological applications, time evolutions of Bloch-Redfield type are widely adopted for modelling open system dynamics, despite their non-positive preserving character: this physical inconsistency, that in general shows up at small times, is usually cured by suitably restricting the space of allowed initial states. Nevertheless, additional problems may arise in relation to entanglement: specifically, we show that Redfield dynamics can generate entanglement through a purely local action, and this unphysical effect can persist for finite times.