Eur. Phys. J. B (2015) 88: 284
https://doi.org/10.1140/epjb/e2015-60247-6

Regular Article

Quantum phase transitions in spin-1 compass chains

¹ Department of Physics, Tianjin Polytechnic University, Tianjin 300387, P.R. China
² College of Physics, Optoelectronics and Energy, Soochow University, Suzhou, Jiangsu 215006, P.R. China

^a e-mail: wlyou@suda.edu.cn

Received: 27 March 2015
Received in final form: 8 July 2015
Published online: 2 November 2015

Abstract

The ground-state phase diagram and quantum phase transitions (QPTs) in a spin-1 compass chain are investigated by the infinite time-evolving block decimation (iTEBD) method. Various phases are discerned by energy densities, spin correlations and entanglement entropy. A generalized string correlator is found to be capable of describing the nonlocal string order in the disordered phase. Furthermore, in the noncritical disordered phase, the spin-spin correlations are found to decay exponentially. Except for a multicritical point (J₁ = 0, J₂ = 0), the QPTs are determined to have second-order characters. In addition, the central charges on these critical phase boundaries are determined to be c = 1 / 2, therefore these QPTs belong to the Ising universality class.