Revealing emergent many-body phenomena by analyzing large-scale space-time records of monitored quantum systems

TL;DR

This paper demonstrates how large-scale space-time data from monitored quantum systems can reveal complex many-body phenomena, using a dissipative spin model relevant to Rydberg quantum simulators.

Contribution

It introduces a method to analyze quantum trajectories with free-energy functionals, uncovering emergent phenomena akin to hydrophobic effects in quantum systems.

Findings

Trajectories reveal complex statistical phenomena in monitored quantum systems.

Hydrophobic-like behavior observed near phase transitions in the model.

Experimental observability and robustness to imperfections discussed.

Abstract

Recent advances in quantum simulators permit unitary evolution interspersed with locally resolved mid-circuit measurements. This paves the way for the observation of large-scale space-time structures in quantum trajectories and opens a window for the \emph{in situ} analysis of complex dynamical processes. We demonstrate this idea using a paradigmatic dissipative spin model, which can be implemented, e.g., on Rydberg quantum simulators. Here, already the trajectories of individual experimental runs reveal surprisingly complex statistical phenomena. In particular, we exploit free-energy functionals for trajectory ensembles to identify dynamical features reminiscent of hydrophobic behavior observed near the liquid-vapor transition in the presence of solutes in water. We show that these phenomena are observable in experiments and discuss the impact of common imperfections, such as readout errors and disordered interactions.