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Entanglement and spin squeezing in non-Hermitian phase transitions
Tony E Lee1, Florentin Reiter2, Nimrod Moiseyev3
1ITAMP, Harvard-Smithsonian Center for Astrophysics, Cambridge, Massachusetts 02138, USA and Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA.
Physical Review Letters
|January 3, 2015
Summary
Non-Hermitian dynamics create significant entanglement in many-body systems. This approach enhances quantum metrology, surpassing Hermitian models in spin squeezing and multiparticle entanglement during phase transitions.
Area of Science:
- Quantum physics
- Many-body systems
- Non-Hermitian dynamics
Background:
- Entanglement is a key resource in quantum mechanics.
- Non-Hermitian systems are increasingly studied for unique quantum phenomena.
- The Lipkin-Meshkov-Glick model is a standard testbed for quantum phase transitions.
Purpose of the Study:
- To investigate the role of non-Hermitian dynamics in generating entanglement.
- To analyze entanglement properties during phase transitions in a non-Hermitian model.
- To explore the potential of non-Hermitian dynamics for quantum metrology.
Main Methods:
- Studied the non-Hermitian Lipkin-Meshkov-Glick model.
- Analyzed multiparticle entanglement and spin squeezing.
- Compared results with the Hermitian counterpart.
Main Results:
- Non-Hermitian dynamics generate substantial entanglement.
- Maximum multiparticle entanglement (full N-particle entanglement) occurs at the phase transition.
- The non-Hermitian model shows enhanced spin squeezing compared to the Hermitian model.
Conclusions:
- Non-Hermitian dynamics are a powerful tool for generating entanglement in many-body systems.
- These dynamics offer advantages for quantum metrology applications.
- Experimental feasibility using trapped ions and cavity QED is discussed.
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