arXiv subjects

Nicolaus A. Chlanda

Publications and source records attributed to Nicolaus A. Chlanda.

3 recordsLinked to original sources

arXiv2026

A random sampling method to test the weak Eigenstate Thermalization Hypothesis

We introduce a random sampling method for testing the weak Eigenstate Thermalization Hypothesis (wETH) that is particularly useful for large, sparse Hamiltonians. We test the method on a well-studied Rydberg atom system that exhibits both two- and three-body dipole-dipole interactions. Our results show that our method allows for the study of system sizes significantly beyond the limits of exact diagonalization. We find that the fluctuations in eigenstate expectation values decay as the Hilbert space dimension $D^{-1/2}$, consistent with wETH and in agreement with previous numerical results.

quant-ph↗

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↗