Eur. Phys. J. D (2017) 71: 173
https://doi.org/10.1140/epjd/e2017-80179-5

Regular Article

Thermally stable multipartite entanglements in the frustrated Heisenberg hexagon

Department of Physics, Jadavpur University, 188 Raja Subodh Chandra Mallik Road, 700032 Kolkata, India

^a e-mail: asimkumar96@yahoo.com

Received: 16 March 2017
Received in final form: 18 April 2017
Published online: 22 June 2017

Abstract

Thermally stable quantum states with multipartite entanglements led by frustration are found in the antiferromagnetic spin-1/2 Heisenberg hexagon. The model has been solved exactly to obtain all analytic expressions of eigenvalues and eigenfunctions. Detection and characterizations for various types of entanglements have been carried out in terms of concurrence and entanglement witnesses based on several thermodynamic observables. Variations of entanglement properties with respect to temperature and frustration are discussed. Even though the frustration opposes the bipartite entanglement, it favors the multipartite entanglement. Entangled states exhibit robustness against the thermal effects in the presence of frustration and they are found to survive at any temperature.