Multi-critical dynamics of the Boson system in the vicinity of the second-order quantum phase transition

TL;DR

This paper investigates the complex non-equilibrium critical dynamics of a Boson system near a second-order quantum phase transition, revealing multiple critical regimes and their crossover behavior using the Keldysh technique.

Contribution

It introduces a detailed analysis of multi-critical behavior and regime crossover in quantum critical dynamics of Boson systems near second-order transitions.

Findings

Identification of three critical regimes: AQM, CCDM, QCDM.

Crossover phenomena among different critical modes.

Critical behavior depends on the approach conditions to the critical point.

Abstract

The non-equilibrium dynamics of the critical behaviour of the Boson system undergoing the second order quantum phase transition is discussed. The analysis is carried out using the Keldysh technique of the non-equilibrium dynamics description. The critical behaviour close to the quantum critical point has been shown to be multi-critical. Crossover among three different critical regimes (modes) is possible: adiabatic quantum mode (AQM), dissipative classical mode (classical critical dynamics mode (CCDM) and dissipative quantum critical mode (QCDM). As a result, the observed critical behavior can essentially depend on the conditions of approaching the critical point.