Eur. Phys. J. Plus (2015) 130: 95
https://doi.org/10.1140/epjp/i2015-15095-3

Regular Article

Quantum ground-state entanglement for spin-1/2 alternating Heisenberg model in one spatial dimension

¹ School of Public Health and Management, Chongqing Medical University, 400016, Chongqing, P.R. China
² College of medical informatics, Chongqing Medical University, 400016, Chongqing, P.R. China
³ School of Science, Xian Polytechnic University, 710048, Xi’an, P.R. China

^* e-mail: wanghl@cqmu.edu.cn

Received: 20 January 2015
Revised: 13 April 2015
Accepted: 16 April 2015
Published online: 21 May 2015

Abstract

Quantum entanglement for a one-dimensional quantum antiferromagnetic-ferromagnetic spin-1/2 alternating Heisenberg chain is investigated by employing the infinite matrix product state representation. The entanglement entropies for the model are shown and the peaks of the entropies tell us the quantum phase transitions happen when the control parameter crosses its critical value. Besides, spontaneous magnetization is given and the critical exponent is extracted from the data. Finally, a finite-entanglement scaling of the von Neumann entropy and finite-entanglement scaling exponent are given with different truncation dimension, from which the type of the transition and its conformal anomaly parameter c are obtained at the critical point.