Geometric Squeezing of a Degenerate Fermi Gas

Quantum simulation with ultracold gases provides a highly customizable platform for the study of many-body physics, shedding new light on important physical systems. Magnetic fields or, equivalently in the case of a uniform, static field, rotation are especially important parameters for many-body sy...

Full description

Bibliographic Details
Main Author: Wilson, Cedric Chinua
Other Authors: Zwierlein, Martin W.
Format: Thesis
Published: Massachusetts Institute of Technology 2023
Online Access:https://hdl.handle.net/1721.1/150685
Description
Summary:Quantum simulation with ultracold gases provides a highly customizable platform for the study of many-body physics, shedding new light on important physical systems. Magnetic fields or, equivalently in the case of a uniform, static field, rotation are especially important parameters for many-body systems including nuclear matter, neutron stars, superfluid helium, and clean conductive samples exhibiting the quantum Hall effect. This thesis details the construction of a new experiment to study rapidly-rotating quantum gases, and two experimental results from the new apparatus. The procedure of geometric squeezing utilizes a rotating, elliptical harmonic trap to realize the squeezing Hamiltonian for guiding center motion. We first outline the observation of a geometrically squeezed state of a rapidly-rotating Bose-Einstein condensate entering the lowest Landau level. We also measure its Hall response, analogous to the 𝐸 × 𝐵 drift of charged particles in crossed electric and magnetic fields. We then detail the realization of a geometrically squeezed state of a rapidly rotating, non-interacting atomic Fermi gas and the measurement of its Hall drift velocity. The Fermi gas shrinks down in one direction to a size limited by the width of the highest occupied Landau level. In the orthogonal direction it expands exponentially, at a local speed given by the local Hall drift velocity. We examine the physics away from the rapidly rotating regime and find that it is well described by the phase space evolution of the Fermi surface under the influence of Coriolis and centrifugal forces, in direct analogy to the cranking model for rotating nuclei.