Heat Capacity and Entanglement Measure in a simple two-qubit model

TL;DR

This paper investigates a two-qubit system exhibiting quantum phase transitions, deriving an analytical link between heat capacity and entanglement, and proposing an experimental protocol to measure entanglement.

Contribution

It provides an analytical expression connecting heat capacity and entanglement in a two-qubit model and introduces an experimental protocol for entanglement measurement.

Findings

Analytical relation between heat capacity and entanglement derived

Quantum phase transitions linked to ground state level crossings

Proposed experimental protocol for entanglement measurement

Abstract

A simple two-qubit model showing Quantum Phase Transitions as a consequence of ground state level crossings is studied in detail. Using the Concurrence of the system as an entanglement measure and heat capacity as a marker of thermodynamical properties, an analytical expression giving the latter in terms of the former is obtained. A protocol allowing an experimental measure of entanglement is then presented and compared with a related proposal recently reported by Wie\'sniak, Vedral and Brukner