Eur. Phys. J. B (2016) 89: 31
https://doi.org/10.1140/epjb/e2016-60885-0

Regular Article

Universal scaled Higgs-mass gap for the bilayer Heisenberg model in the ordered phase

Department of Physics, Faculty of Science, Okayama University, 700-8530 Okayama, Japan

^a e-mail: nisiyama@psun.phys.okayama-u.ac.jp

Received: 13 November 2015
Received in final form: 31 December 2015
Published online: 3 February 2016

Abstract

The spectral properties for the bilayer quantum Heisenberg model were investigated with the numerical diagonalization method. In the ordered phase, there appears the massive Higgs excitation embedded in the continuum of the Goldstone excitations. Recently, it was claimed that the properly scaled Higgs mass is a universal constant in proximity to the critical point. Diagonalizing the finite-size cluster with N ≤ 36 spins, we calculated the dynamical scalar susceptibility , which is rather insensitive to the Goldstone mode. A finite-size-scaling analysis of is made, and the universal (properly scaled) Higgs mass is estimated.