Spin-wave analysis of the transverse-field Ising model on the checkerboard lattice
Abstract
The ground state properties of the S=1/2 transverse-field Ising model on the checkerboard lattice are studied using linear spin wave theory. We consider the general case of different couplings between nearest neighbors (J1) and next-to-nearest neighbors (J2). In zero field the system displays a large degeneracy of the ground state, which is exponential in the system size (for J1=J2) or in the system's linear dimensions (for J2>J1). Quantum fluctuations induced by a transverse field are found to be unable to lift this degeneracy in favor of a classically ordered state at the harmonic level. This remarkable fact suggests that a quantum-disordered ground state can be instead promoted when non-linear fluctuations are accounted for, in agreement with existing results for the isotropic case J1=J2. Moreover spin-wave theory shows sizable regions of instability which are further candidates for quantum-disordered behavior.
Keywords
Cite
@article{arxiv.1202.1462,
title = {Spin-wave analysis of the transverse-field Ising model on the checkerboard lattice},
author = {Louis-Paul Henry and Peter C. W. Holdsworth and Frédéric Mila and Tommaso Roscilde},
journal= {arXiv preprint arXiv:1202.1462},
year = {2015}
}
Comments
12 pages, 13 figures