Heat Capacity and Entanglement Measure in a simple two-qubit model
  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 
B.Leggio, A. Napoli, H. Nakazato, A. Messina
quant-ph