Criteria for two-dimensional kinematics in an interacting Fermi gas

Rapid Communication

Criteria for two-dimensional kinematics in an interacting Fermi gas

P. Dyke, K. Fenech, T. Peppler, M. G. Lingham, S. Hoinka, W. Zhang, S.-G. Peng, B. Mulkerin, H. Hu, X.-J. Liu, and C. J. Vale

Phys. Rev. A 93, 011603(R) – Published 14 January 2016

Abstract

Ultracold Fermi gases subject to tight transverse confinement offer a highly controllable setting to study the two-dimensional (2D) BCS to Berezinskii-Kosterlitz-Thouless superfluid crossover. Achieving the 2D regime requires confining particles to their transverse ground state which presents challenges in interacting systems. Here, we establish the conditions for an interacting Fermi gas to display 2D kinematics. Transverse excitations are detected by measuring the transverse expansion rate which displays a sudden increase when the atom number exceeds a critical value $N_{2 D}$ signifying a density driven departure from 2D kinematics. For weak interactions $N_{2 D}$ is set by the aspect ratio of the trap. Close to a Feshbach resonance, however, the stronger interactions reduce $N_{2 D}$ and excitations appear at lower density.

Received 14 November 2014

DOI:https://doi.org/10.1103/PhysRevA.93.011603

Physics Subject Headings (PhySH)

Fermi gases Fermionic condensates

Atomic, Molecular & OpticalGeneral Physics

Authors & Affiliations

P. Dyke¹, K. Fenech¹, T. Peppler¹, M. G. Lingham¹, S. Hoinka¹, W. Zhang², S.-G. Peng³, B. Mulkerin¹, H. Hu¹, X.-J. Liu¹, and C. J. Vale^1,*

¹Centre for Quantum and Optical Sciences, Swinburne University of Technology, Melbourne 3122, Australia
²Department of Physics and Beijing Key Laboratory of Opto-Electronic Functional Materials and Micro-Nano Devices, Renmin University of China, Beijing 100872, China
³State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071, China

^*Author to whom correspondence should be addressed: cvale@swin.edu.au

Article Text (Subscription Required)

Click to Expand

Supplemental Material (Subscription Required)

Click to Expand

References (Subscription Required)

Click to Expand

Issue

Vol. 93, Iss. 1 — January 2016

Reuse & Permissions

Access Options

Author publication services for translation and copyediting assistance advertisement

Physical Review A

covering atomic, molecular, and optical physics and quantum information