Rydberg impurity in a Fermi gas: Quantum statistics and rotational blockade

Abstract

We consider the quench of an atomic impurity via a single Rydberg excitation in a degenerate Fermi gas. The Rydberg interaction with the background gas particles induces an ultralong-range potential that binds particles to form dimers, trimers, tetramers, etc. Such oligomeric molecules were recently observed in atomic Bose-Einstein condensates. In this work, we demonstrate with a functional determinant approach that quantum statistics and fluctuations have observable spectral consequences. We show that the occupation of molecular states is predicated on the Fermi statistics, which suppresses molecular formation in an emergent molecular shell structure. At large gas densities this leads to spectral narrowing, which can serve as a probe of the quantum gas thermodynamic properties.

Creation of vibrationally-excited ultralong-range Rydberg molecules in polarized and unpolarized cold gases of 87Sr

“…Furthermore, since Λ is preserved during the Franck-Condon transition, the contribution to rotational energy splitting from the centrifugal potential present in both the initial and final states largely cancels out. The contributions of different rotational channels to the Rydberg molecule excitation spectrum were recently discussed in reference [19]. Unlike the case for ground-state molecules, the molecular wavefunctions for excited Rydberg dimers span multiple wells (see Figs.…”

Dynamics of atoms within atoms

“…In this work we numerically analyze how Rydberg atoms excited within a BEC affect the latter, discussing multiple effects that go beyond earlier studies [14,17,20]. Most importantly we segregate the different condensate dynamics induced by the small, highly-oscillatory radial features of the Rydberg-ground-state potential, from the slower dynamics due to the classically averaged potential on larger scales.…”

Cold chemistry: a few-body perspective on impurity physics of a single ion in an ultracold bath

“…The polaron idea plays a crucial role in understanding phenomena of condensed matter physics like colossal magnetoresistance [46,47], charge transport in organic semiconductors [48][49][50], and high-temperature superconductivity [51][52][53]. Indeed, it has been possible to study the polaron model beyond the paradigm of material science thanks to atomic and molecular systems at ultracold temperatures [54][55][56][57][58][59][60][61][62][63].…”