Measurement of the Homogeneous Contact of a Unitary Fermi gas

Abstract

By selectively probing the center of a trapped gas, we measure the local, or homogeneous, contact of a unitary Fermi gas as a function of temperature. Tan's contact, C, is proportional to the derivative of the energy with respect to the interaction strength, and is thus an essential thermodynamic quantity for a gas with short-range correlations. Theoretical predictions for the temperature dependence of C differ substantially, especially near the superfluid transition, Tc, where C is predicted to either sharply decrease, sharply increase, or change very little. For T/T_F>0.4, our measurements of the homogeneous gas contact show a gradual decrease of C with increasing temperature, as predicted by theory. We observe a sharp decrease in C at T/T_F=0.16, which may be due to the superfluid phase transition. While a sharp decrease in C below Tc is predicted by some many-body theories, we find that none of the predictions fully accounts for the data.

5 pages, including a supplementary material section (10 pages). Rewriting of the introduction and discussion sections

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Cited by in corpus (25)

• Precise determination of the structure factor and contact in a unitary Fermi gas
• Breakdown of Fermi liquid description for strongly interacting fermions
• Spectral response and contact of the unitary Fermi gas
• Fluid Dynamics and Viscosity in Strongly Correlated Fluids
• Contact and sum-rules in a near-uniform Fermi gas at unitarity
• Experimental evaluation of the nuclear neutron-proton contact
• Superfluid Fermi atomic gas as a quantum simulator for the study of neutron-star equation of state
• Connecting few-body inelastic decay to many-body correlations: a weakly coupled impurity in a resonant Fermi gas
• Large-momentum distribution of a polarized Fermi gas and p-wave contacts
• High-momentum distribution with subleading $k^{-3}$ tail in the odd-wave interacting one-dimensional Fermi gases
• Universal Tan relations for quantum gases in one dimension
• Universality of the unitary Fermi gas: A few-body perspective
• Critical behaviours of contact near phase transitions
• P-Wave Contact Tensor -- Universal Properties of Axisymmetry-Broken P-Wave Fermi Gases
• Expansion of harmonically trapped interacting particles and time dependence of the contact
• Tan contact and universal high momentum behavior of the fermion propagator in the BCS-BEC crossover
• Sigature of the universal super Efimov Effect: three-body contact in two dimensional Fermi gases
• Contact and Structure Factor for Bosonic and Fermionic Mixtures
• Critical phenomena in one dimension from a Bethe ansatz perspective
• Momentum-resolved spectroscopy of a Fermi liquid
• Short range correlations - The important role of few-body dynamics in many-body systems
• Equation of State of Neutron-Rich Matter in $d$-Dimensions
• Tan's contact as an indicator of completeness and self-consistency of a theory
• P-wave contacts of quantum gases in quasi-one-dimensional and quasi-two-dimensional traps
• Photo-excitation measurement of Tan's contact for a strongly interacting Fermi gas