Volume 77, Number 1, January 2007
Article Number 17001
Number of page(s) 5
Section Condensed Matter: Electronic Structure, Electrical, Magnetic and Optical Properties
Published online 27 December 2006
EPL, 77 (2007) 17001
DOI: 10.1209/0295-5075/77/17001

Entanglement crossover close to a quantum critical point

L. Amico and D. Patanè

MATIS CNR-INFM and Dipartimento di Metodologie Fisiche e Chimiche (DMFCI), Università di Catania - viale A. Doria 6, 95125 Catania, Italy

received 6 September 2006; accepted in final form 3 November 2006; published January 2007
published online 27 December 2006

We discuss the thermal entanglement close to a quantum phase transition by analyzing the pairwise entanglement for one-dimensional models in the quantum Ising universality class. We demonstrate that the entanglement sensitivity to thermal and to quantum fluctuations obeys universal $T\ne 0$-scaling laws. We show that the entanglement exhibits a peculiar universal crossover behaviour, shedding light on the mechanisms bringing quantum criticality up to finite temperatures.

75.10.Jm - Quantized spin models .
03.65.Ud - Entanglement and quantum nonlocality (e.g. EPR paradox, Bell's inequalities, GHZ states, etc.) .
05.30.-d - Quantum statistical mechanics .

© Europhysics Letters Association 2007