Exact spectrum of the Lipkin-Meshkov-Glick model in the thermodynamic limit and finite-size corrections
Exact spectrum of the Lipkin-Meshkov-Glick model in the thermodynamic limit and finite-size corrections
The spectrum of the Lipkin-Meshkov-Glick model is exactly derived in the thermodynamic limit by means of a spin-coherent-state formalism. In the first step, a classical analysis allows one to distinguish between four distinct regions in the parameter space according to the nature of the singularities arising in the classical energy …