Probing spin-motion coupling of two Rydberg atoms by a Stern-Gerlach-like experiment

TL;DR

This paper demonstrates a protocol to measure and visualize the spin-motion coupling in Rydberg atoms, revealing interaction-induced dynamics and state-dependent trajectories through a Stern-Gerlach-like experiment.

Contribution

It introduces a novel experimental protocol for probing spin-motion coupling in Rydberg atoms, combining internal state and position readout in a controlled setup.

Findings

Velocities match theoretical predictions for van der Waals repulsion

Observation of oscillatory dynamics near a macrodimer state

Separation of atomic wavepackets demonstrates spin-motion coupling

Abstract

We propose and implement a protocol to measure the state-dependent motion of Rydberg atoms induced by dipole-dipole interactions. Our setup enables simultaneous readout of both the atomic internal state and position on a one-dimensional array of optical tweezers. We benchmark the protocol using two atoms in the same Rydberg state, which experience van der Waals repulsion, and measure velocities in agreement with theoretical predictions. When preparing the atoms in a different pair state, we observe an oscillatory dynamics that we attribute to the proximity of a macrodimer bound state. Finally, we perform a Stern-Gerlach-like experiment in which a superposition of the two previous pair states results in the separation of the atomic wavepacket into two macroscopically distinct trajectories, thereby demonstrating spin-motion coupling mediated by the interactions.