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Published on: June 7, 2018
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Squeezed Light Induced Symmetry Breaking Superradiant Phase Transition.
C J Zhu1, L L Ping1, Y P Yang1
1MOE Key Laboratory of Advanced Micro-Structured Materials, School of Physics Science and Engineering, Tongji University, Shanghai 200092, China.
Physical Review Letters
|March 7, 2020
Summary
Squeezed light induces quantum phase transitions in qubit systems without ultrastrong coupling. This research reveals a tricritical point and controllable phase transitions, offering insights into quantum optics and condensed matter physics.
Area of Science:
- Quantum physics
- Quantum optics
- Condensed matter physics
Background:
- Collective quantum systems, such as qubits in optical cavities, are crucial for quantum technologies.
- Quantum phase transitions (QPTs) typically require ultrastrong coupling between system components.
- Squeezed light, a non-classical state of light, can modify quantum system dynamics.
Purpose of the Study:
- To theoretically investigate quantum phase transitions in qubit-cavity systems using squeezed light.
- To explore the possibility of achieving QPTs without the need for ultrastrong coupling.
- To identify control mechanisms and potential applications of such transitions.
Main Methods:
- Theoretical analysis using standard mean-field theory.
- Modeling of a cavity field squeezed via optical parametric amplification.
- Derivation of conditions for quantum phase transitions.
Main Results:
- Squeezed light induces symmetry breaking, leading to QPTs without ultrastrong coupling.
- A tricritical point is identified where first- and second-order phase transitions merge.
- Phase transitions are controllable via the nonlinear gain coefficient, influenced by pump field intensity.
- Optical switching between normal and superradiant phases is achieved by adjusting pump field intensity.
Conclusions:
- The study demonstrates a novel pathway to induce and control quantum phase transitions using squeezed light.
- The findings offer new possibilities for manipulating quantum states and implementing optical switches.
- The proposed mechanism is applicable to diverse quantum systems, including atomic, solid-state, and circuit QED platforms.
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