Collective Modes in the Cooperative Jahn-Teller Model: Path Integral Approach

TL;DR

This paper analyzes the collective excitations and phase transitions in the cooperative Jahn-Teller model, revealing magnetic ordering, bosonic condensates, and characteristic excitation modes using a mean-field approach.

Contribution

It provides an analytical approximation of the ground-state phase diagram and elementary excitations for the cooperative Jahn-Teller model in quantum optical systems.

Findings

Identification of a quantum magnetic structural phase transition

Existence of one gapless Goldstone mode

Presence of two gapped amplitude modes

Abstract

We discuss analytical approximations to the ground-state phase diagram and the elementary excitations of the cooperative Jahn-Teller model describing strongly correlated spin-boson system on a lattice in various quantum optical systems. Based on the mean-field theory approach we show that the system exhibits quantum magnetic structural phase transition which leads to magnetic ordering of the spins and formation of the bosonic condensates. We determine existing of one gapless Goldstone mode and two gapped amplitude modes inside the symmetry-broken phase.