Dynamical Quantum Phase Transitions in Interacting Atomic Interferometers

TL;DR

This paper demonstrates that interactions in atomic interferometers induce dynamical quantum phase transitions, leading to exotic quantum states and offering new avenues for quantum metrology beyond the standard quantum limit.

Contribution

It reveals how interactions cause dynamical quantum phase transitions in atomic interferometers and links these to the formation of pair condensates and highly entangled states.

Findings

Dynamical quantum phase transitions occur at zeros of Loschmidt echo.

Transitions signify the emergence of pair condensates with strong two-body correlations.

Interacting atomic interferometers can generate entangled states to surpass standard quantum limits.

Abstract

Particle-wave duality has allowed physicists to establish atomic interferometers as celebrated complements to their optical counterparts in a broad range of quantum devices. However, interactions naturally lead to decoherence and have been considered as a longstanding obstacle in implementing atomic interferometers in precision measurements. Here, we show that interactions lead to dynamical quantum phase transitions between Schr\"{o}dinger's cats in an atomic interferometer. These transition points result from zeros of Loschmidt echo, which approach the real axis of the complex time plane in the large particle number limit, and signify pair condensates, another type of exotic quantum states featured with prevailing two-body correlations. Our work suggests interacting atomic interferometers as a new tool for exploring dynamical quantum phase transitions and creating highly entangled states to beat the standard quantum limit.