Direct observation of ultrafast many-body electron dynamics in an ultracold Rydberg gas

TL;DR

This paper demonstrates the real-time observation of ultrafast many-body electron dynamics in an ultracold Rydberg gas using attosecond precision interferometry, revealing phase shifts due to many-body correlations.

Contribution

It introduces an experimental method to directly observe and control ultrafast quantum many-body dynamics in Rydberg gases, advancing understanding of non-equilibrium quantum systems.

Findings

Ultrafast electronic coherence oscillates with a 1 femtosecond period.

Phase shifts in coherence are consistent with many-body correlations.

Dynamics can be controlled by tuning Rydberg state parameters.

Abstract

Many-body correlations govern a variety of important quantum phenomena such as the emergence of superconductivity and magnetism. Understanding quantum many-body systems is thus one of the central goals of modern sciences. Here we demonstrate an experimental approach towards this goal by utilizing an ultracold Rydberg gas generated with a broadband picosecond laser pulse. We follow the ultrafast evolution of its electronic coherence by time-domain Ramsey interferometry with attosecond precision. The observed electronic coherence shows an ultrafast oscillation with a period of 1 femtosecond, whose phase shift on the attosecond timescale is consistent with many-body correlations among Rydberg atoms beyond mean-field approximations. This coherent and ultrafast many-body dynamics is actively controlled by tuning the orbital size and population of the Rydberg state, as well as the mean atomic distance. Our approach will offer a versatile platform to observe and manipulate non-equilibrium dynamics of quantum many-body systems on the ultrafast timescale.