arXiv subjects

Sarah E. Spielman

Publications and source records attributed to Sarah E. Spielman.

3 recordsLinked to original sources

arXiv2026

Thermalization within a Stark manifold through Rydberg atom interactions

We use dynamical quantum typicality to predict the thermal equilibrium state of ultracold Rydberg atoms exchanging energy via long-range dipole-dipole interactions. We excite atoms to the center of a manifold of nearly-harmonically spaced clusters of Stark energy levels and then allow them to equilibrate. Comparing the equilibrium state to our thermal prediction across a range of Rydberg densities, we find that this system generally fails to thermalize, though it approaches the thermal state at the highest tested density. This is the first direct comparison of a dynamical quantum typicality calculation to experiment.

quant-ph↗

arXiv2026

Energy Transport Among Highly-Polarized Atoms

We measure the transport of energy among the internal states of ultracold rubidium Rydberg atoms coupled by dipole-dipole exchange. In a magneto-optical trap, a static electric field of a few V/cm shifts the energy levels of the atoms. For a particular principal quantum number, $n$, the angular momentum eigenstates $\ell > 4$ are nearly degenerate at zero electric field. At nonzero field, a manifold of equally spaced clusters form a ladder with each rung consisting of a set of closely spaced $m$ energy eigenstates. We excite Rydberg atoms to energy levels near the center of the manifold and allow them to exchange energy via resonant dipole-dipole interactions. We measure the time evolution as energy spreads away from the center of the manifold, which reveals that the system may fail to thermalize for long interaction times. A computational model that includes only a few essential features of the system qualitatively agrees with this result.

physics.atom-ph↗

arXiv2024

Quantum Many-Body Scars in Few-Body Dipole-Dipole Interactions

We simulate the dynamics of Rydberg atoms resonantly exchanging energy via two-, three-, and four-body dipole-dipole interactions in a one-dimensional array. Using simplified models of a realistic experimental system, we study the initial state survival probability, mean level spacing, spread of entanglement, and properties of the energy eigenstates. By exploring a range of disorders and interaction strengths, we find regions in parameter space where the three- and four-body dynamics either fail to thermalize or do so slowly. The interplay between the stronger hopping and weaker field-tuned interactions gives rise to quantum many-body scar states, which play a critical role in slowing the dynamics of the three- and four-body interactions.

quant-ph↗