Verification of universal relations in a strongly interacting Fermi gas

Abstract

Many-body fermion systems are important in many branches of physics, including condensed matter, nuclear, and now cold atom physics. In many cases, the interactions between fermions can be approximated by a contact interaction. A recent theoretical advance in the study of these systems is the derivation of a number of exact universal relations that are predicted to be valid for all interaction strengths, temperatures, and spin compositions. These equations, referred to as the Tan relations, relate a microscopic quantity, namely, the amplitude of the high-momentum tail of the fermion momentum distribution, to the thermodynamics of the many-body system. In this work, we provide experimental verification of the Tan relations in a strongly interacting gas of fermionic atoms. Specifically, we measure the fermion momentum distribution using two different techniques, as well as the rf excitation spectrum and determine the effect of interactions on these microscopic probes. We then measure the potential energy and release energy of the trapped gas and test the predicted universal relations.

11 pages, 4 figures

References in corpus (13)

• Using photoemission spectroscopy to probe a strongly interacting Fermi gas
• Generalized Virial Theorem and Pressure Relation for a strongly correlated Fermi gas
• Molecular Probe of Pairing in the BEC-BCS Crossover
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• The potential energy of a ${}^{40}$K Fermi gas in the BCS-BEC crossover
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• Radio frequency spectroscopy of a strongly imbalanced Feshbach-resonant Fermi gas
• Final-state effects in the radio frequency spectrum of strongly interacting fermions

Cited by in corpus (9)

• Observation of pseudogap behavior in a strongly interacting Fermi gas
• Universal Relations for Identical Bosons from 3-Body Physics
• BEC-BCS crossover and universal relations in unitary Fermi gases
• Momentum Distribution and Contact of the Unitary Fermi gas
• Universal contact of strongly interacting fermions at finite temperatures
• Temperature and coupling dependence of the universal contact intensity for an ultracold Fermi gas
• Single-Particle Momentum Distribution of an Efimov trimer
• Cold Fermi-gas with long range interaction in a harmonic trap
• Universal Relations for Fermions with Large Scattering Length