Full-Counting Many-Particle Dynamics: Nonlocal and Chiral Propagation of Correlations

TL;DR

This paper extends full-counting statistics to nonequilibrium many-particle systems, revealing nonlocal and chiral correlation propagation, oscillatory entanglement growth, and violations of Lieb-Robinson bounds, especially near a spectral transition point.

Contribution

It introduces a novel application of full-counting statistics to open quantum dynamics, demonstrating unique correlation phenomena in an exactly solvable model.

Findings

Correlations propagate beyond Lieb-Robinson bounds.

Chiral and nonlocal correlation propagation observed.

Oscillatory entanglement growth during quench dynamics.

Abstract

The ability to measure single quanta has allowed complete characterization of small quantum systems such as quantum dots in terms of statistics of detected signals known as full-counting statistics. Quantum gas microscopy enables one to observe many-body systems at the single-atom precision. We extend the idea of full-counting statistics to nonequilibrium open many-particle dynamics and apply it to discuss the quench dynamics. By way of illustration, we consider an exactly solvable model to demonstrate the emergence of unique phenomena such as nonlocal and chiral propagation of correlations, leading to a concomitant oscillatory entanglement growth. We find that correlations can propagate beyond the conventional maximal speed, known as the Lieb-Robinson bound, at the cost of probabilistic nature of quantum measurement. These features become most prominent at the real-to-complex spectrum transition point of an underlying parity-time-symmetric effective non-Hermitian Hamiltonian. A possible experimental realization with quantum gas microscopy is discussed.