Entanglement and the Thermodynamic Arrow of Time

TL;DR

This paper explores how quantum entanglement relates to the thermodynamic arrow of time, introducing a new entanglement witness based on thermodynamic transformations and analyzing multipartite systems and experimental possibilities.

Contribution

It introduces a novel entanglement witness linked to thermodynamic state transformations and extends the analysis to multipartite systems with reversed thermodynamic arrows.

Findings

Transformation between thermodynamic states acts as an entanglement witness.

Multipartite entangled systems can exhibit large reversals of the thermodynamic arrow.

Proposes experimental demonstrations with small numbers of qubits.

Abstract

We discuss quantum entanglement in the context of the thermodynamic arrow of time. We review the role of correlations in entropy-decreasing events and prove that the occurrence of a transformation between two thermodynamic states constitutes a new type of entanglement witness, one not defined as a separating plane in state space between separable and entangled states, but as a physical process dependent on the local initial properties of the states. Extending work by Partovi, we consider a general entangled multipartite system that allows large reversals of the thermodynamic arrow of time. We describe a hierarchy of arrows that arises from the different correlations allowed in a quantum state and examine these features in the context of Maxwell's Demon. We examine in detail the case of three qubits, and also propose some simple experimental demonstrations possible with small numbers of qubits.