Guang-Qiang Zhong, Shou-Shu Gong, Qing-Rong Zheng, Gang Su ^∗
College of Physical Sciences, Graduate University of Chinese Academy of Sciences, PO Box 4588, Beijing 100049, China

Abstract:

The magnetic behaviors of a spin-1 / 2 alternating Heisenberg antiferromagnetic chain in a staggered transverse magnetic field is studied by means of the density-matrix renormalization group method and Jordan–Wigner transformation. Quantum phase transitions of different types are observed in the S = 1 Néel and XY-like gapless phases, which result from the competitions between the staggered transverse field and magnetic orders induced by anisotropy and alternating interactions. The results are compared with the mean-field and some exactly resolved results.