Entanglement and spin squeezing in non-Hermitian phase transitions

TL;DR

This paper demonstrates that non-Hermitian phase transitions in many-body systems lead to maximal entanglement and enhanced spin squeezing, offering new avenues for quantum metrology and understanding quantum phase transitions.

Contribution

It reveals that non-Hermitian dynamics induce maximum multiparticle entanglement at phase transitions, surpassing Hermitian models in spin squeezing capabilities.

Findings

Maximum N-particle entanglement at non-Hermitian phase transition

Enhanced spin squeezing compared to Hermitian models

Potential for improved quantum metrology applications

Abstract

We show that non-Hermitian dynamics generate substantial entanglement in many-body systems. We consider the non-Hermitian Lipkin-Meshkov-Glick model and show that its phase transition occurs with maximum multiparticle entanglement: there is full N-particle entanglement at the transition, in contrast to the Hermitian case. The non-Hermitian model also exhibits more spin squeezing than the Hermitian model, showing that non-Hermitian dynamics are useful for quantum metrology. Experimental implementations with trapped ions and cavity QED are discussed.