Quantum Multicritical Behavior for Coupled Optical Cavities with Driven Laser Fields

TL;DR

This paper investigates quantum multicritical points in a generalized Dicke model involving coupled optical cavities and driven laser fields, demonstrating their controllability and evolution into Lifshitz points, with implications for quantum phase transition physics.

Contribution

It introduces a system with tunable multicritical points in a generalized Dicke model and explores their evolution into Lifshitz points under periodic modulation of the Rabi frequency.

Findings

Multicritical points occur in the system and can be manipulated via system parameters.

Quantum critical points can evolve into Lifshitz points with periodic Rabi frequency modulation.

Atomic pseudo-spin textures characterize quantum critical behaviors.

Abstract

Quantum phase transitions with multicritical points are fascinating phenomena occurring in interacting quantum many-body systems. However, multicritical points predicted by theory have been rarely verified experimentally; finding multicritical points with specific behaviors and realizing their control remains a challenging topic. Here, we propose a system that a quantized light field interacts with a two-level atomic ensemble coupled by microwave fields in optical cavities, which is described by a generalized Dicke model. Multicritical points for the superradiant quantum phase transition are shown to occur. We determine the number and position of these critical points and demonstrate that they can be effectively manipulated through the tuning of system parameters. Particularly, we find that the quantum critical points can evolve into a Lifshitz point if the Rabi frequency of the light field is modulated periodically in time. Remarkably, the texture of atomic pseudo-spins can be used to characterize the quantum critical behaviors of the system. The magnetic orders of the three phases around the Lifshitz point, represented by the atomic pseudo-spins, are similar to those of an axial next-nearest-neighboring Ising model. The results reported here are beneficial for unveiling intriguing physics of quantum phase transitions and pave the way towards to find novel quantum multicritical phenomena based on the generalized Dicke model.