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Spontaneous T-symmetry breaking and exceptional points in cavity quantum electrodynamics systems
Yu-Kun Lu1, Pai Peng2, Qi-Tao Cao1
1State Key Laboratory for Mesoscopic Physics and Collaborative Innovation Center of Quantum Matter, School of Physics, Peking University, Beijing 100871, China; Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan 030006, China.
Science Bulletin
|January 20, 2023
Summary
This study demonstrates spontaneous time-reversal symmetry breaking in cavity quantum electrodynamics. This quantum phenomenon, controlled by atomic detuning and coupling, enables topological manipulation of quantum states.
Area of Science:
- Quantum Physics
- Cavity Quantum Electrodynamics
- Symmetry Breaking
Background:
- Spontaneous symmetry breaking is a fundamental concept in modern physics.
- Cavity quantum electrodynamics (CQED) systems offer a platform for exploring quantum phenomena.
Purpose of the Study:
- To theoretically demonstrate spontaneous time-reversal symmetry breaking in a CQED system.
- To investigate the control parameters and observable effects of this symmetry breaking.
Main Methods:
- Modeling a CQED system with an atomic ensemble and a single resonant cavity mode.
- Describing the interacting system as two coupled oscillators with positive and negative mass.
- Analyzing the parameter space to identify symmetry broken and unbroken phases.
Main Results:
- The spontaneous time-reversal symmetry breaking occurs in the described CQED system.
- Atomic detuning and cavity coupling strength control the symmetry breaking.
- A spectral singularity (exceptional point) separates the symmetry phases.
- Chiral mode switching is observed during quasi-adiabatic dynamics around the singularity.
Conclusions:
- The study theoretically establishes spontaneous time-reversal symmetry breaking in CQED.
- The identified exceptional points and chiral dynamics offer pathways for topological manipulation of quantum states.
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