Spin-liquid state of Wigner-Jordan fermions of the quantum antiferromagnetic Heisenberg model on a triangular lattice

Abstract

A disordered spin state, the nearest-neighbor virtual bonding state of Wigner-Jordan fermions, of the quantum antiferromagnetic Heisenberg model on a triangular lattice is found to have a zero-temperature energy -1.106J per spin, lower than that calculated from spin-wave theories, and in excellent agreement with that from numerical calculations, (-1.094±0.018)J per spin. The excitations of the state are Wigner-Jordan fermions with a gapless spectrum. The low-temperature specific heat is predicted to be proportional to ${\mathit{T}}^{\nu }$, with ν between 2/3 and 1, significantly deviating from the spin-wave prediction, ${\mathit{T}}^2$. At higher temperature, a broad peak in the specific heat near T/2J≊0.75 is also predicted.