Skip to main content
U.S. Department of Energy
Office of Scientific and Technical Information

Contact in the Unitary Fermi Gas across the Superfluid Phase Transition

Journal Article · · Physical Review Letters
 [1];  [2];  [3]
  1. Yale University, New Haven, CT (United States); Yale University, CT (United States)
  2. Central Washington University, Ellensburg, WA (United States); Honeywell Quantum Solutions, Broomfield, CO (United States)
  3. Yale University, New Haven, CT (United States)
A quantity known as the contact is a fundamental thermodynamic property of quantum many-body systems with short-range interactions. Determination of the temperature dependence of the contact for the unitary Fermi gas of infinite scattering length has been a major challenge, with different calculations yielding qualitatively different results. Here we use finite-temperature auxiliary-field quantum Monte Carlo (AFMC) methods on the lattice within the canonical ensemble to calculate the temperature dependence of the contact for the homogeneous spin-balanced unitary Fermi gas. We extrapolate to the continuum limit for 40, 66, and 114 particles, eliminating systematic errors due to finite-range effects. We observe a dramatic decrease in the contact as the superfluid critical temperature is approached from below, followed by a gradual weak decrease as the temperature increases in the normal phase. Our theoretical results are in excellent agreement with the most recent precision ultracold atomic gas experiments. Here, we also present results for the energy as a function of temperature in the continuum limit.
Research Organization:
Yale University, New Haven, CT (United States)
Sponsoring Organization:
USDOE Office of Science (SC), Nuclear Physics (NP)
Grant/Contract Number:
AC02-05CH11231; FG02-00ER41132; FG02-91ER40608; SC0019521
OSTI ID:
1644301
Journal Information:
Physical Review Letters, Journal Name: Physical Review Letters Journal Issue: 4 Vol. 125; ISSN 1079-7114; ISSN 0031-9007
Publisher:
American Physical Society (APS)Copyright Statement
Country of Publication:
United States
Language:
English

References (65)

Superfluid Pairing in Neutrons and Cold Atoms text January 2012
Thermodynamic Measurements in a Strongly Interacting Fermi Gas journal November 2008
Generalized virial theorem and pressure relation for a strongly correlated Fermi gas journal December 2008
Energetics of a strongly correlated Fermi gas journal December 2008
Large momentum part of a strongly correlated Fermi gas journal December 2008
Viscosity and scale invariance in the unitary Fermi gas journal March 2011
Stabilizing canonical-ensemble calculations in the auxiliary-field Monte Carlo method journal March 2015
Virial expansion for a strongly correlated Fermi system and its application to ultracold atomic Fermi gases journal March 2013
Exploring the thermodynamics of a universal Fermi gas journal February 2010
Enhanced paraconductivity-like fluctuations in the radiofrequency spectra of ultracold Fermi atoms journal August 2009
Pre-pairing for condensation journal August 2010
Review of pseudogaps in strongly interacting Fermi gases journal September 2017
Universal contact of strongly interacting fermions at finite temperatures journal March 2011
The Fermi–Hubbard model at unitarity journal August 2006
Three fermions in a box at the unitary limit: universality in a lattice model journal October 2007
Quantum Monte Carlo approaches to nuclear and atomic physics journal January 2012
Sum-rule analysis of radio-frequency spectroscopy of ultracold Fermi gas journal March 2008
Quantum Monte Carlo simulations of the BCS-BEC crossover at finite temperature journal August 2008
Universal relations for a strongly interacting Fermi gas near a Feshbach resonance journal November 2008
Universal properties of the ultracold Fermi gas journal February 2009
Particle distribution tail and related energy formula journal May 2009
Viscosity of strongly interacting quantum fluids: Spectral functions and sum rules journal May 2010
Short-distance and short-time structure of a unitary Fermi gas journal June 2010
Temperature and coupling dependence of the universal contact intensity for an ultracold Fermi gas journal August 2010
Thermodynamics of balanced and slightly spin-imbalanced Fermi gases at unitarity journal November 2010
BEC-BCS crossover and universal relations in unitary Fermi gases journal April 2011
Virial expansion with Feynman diagrams journal November 2011
Auxiliary-field quantum Monte Carlo method for strongly paired fermions journal December 2011
Equation of state of the unitary Fermi gas: An update on lattice calculations journal May 2012
Probing strongly interacting atomic gases with energetic atoms journal May 2012
General relations for quantum gases in two and three dimensions: Two-component fermions journal July 2012
Lattice Monte Carlo calculations for unitary fermions in a finite box journal February 2013
Pair condensation in a finite trapped Fermi gas journal December 2013
High-temperature expansion for interacting fermions journal November 2015
Numerical study of the unitary Fermi gas across the superfluid transition journal May 2016
Diagrammatic Monte Carlo algorithm for the resonant Fermi gas journal January 2019
Exact Relations for a Strongly Interacting Fermi Gas from the Operator Product Expansion journal May 2008
Short-Time Operator Product Expansion for rf Spectroscopy of a Strongly Interacting Fermi Gas journal June 2010
Verification of Universal Relations in a Strongly Interacting Fermi Gas journal June 2010
Universal Behavior of Pair Correlations in a Strongly Interacting Fermi Gas journal August 2010
Temperature Dependence of the Universal Contact Parameter in a Unitary Fermi Gas journal April 2011
Momentum Distribution and Contact of the Unitary Fermi Gas journal May 2011
Resonantly Interacting Fermions in a Box journal June 2011
Measurement of the Homogeneous Contact of a Unitary Fermi Gas journal November 2012
Precise Determination of the Structure Factor and Contact in a Unitary Fermi Gas journal January 2013
Homogeneous Atomic Fermi Gases journal March 2017
Contact and Momentum Distribution of the Unitary Fermi Gas journal September 2018
Contact and Sum Rules in a Near-Uniform Fermi Gas at Unitarity journal May 2019
Spectral Response and Contact of the Unitary Fermi Gas journal May 2019
Pairing Correlations across the Superfluid Phase Transition in the Unitary Fermi Gas journal March 2020
Equation of State of a Fermi Gas in the BEC-BCS Crossover: A Quantum Monte Carlo Study journal November 2004
Momentum Distribution of a Fermi Gas of Atoms in the BCS-BEC Crossover journal December 2005
Spin 1 / 2 Fermions in the Unitary Regime: A Superfluid of a New Type journal March 2006
Critical Temperature and Thermodynamics of Attractive Fermions at Unitarity journal April 2006
Theory of rf-Spectroscopy of Strongly Interacting Fermions journal October 2007
Coherence and Clock Shifts in Ultracold Fermi Gases with Resonant Interactions journal November 2007
Deep Inelastic Scattering on Ultracold Gases journal March 2017
The Equation of State of a Low-Temperature Fermi Gas with Tunable Interactions journal April 2010
Revealing the Superfluid Lambda Transition in the Universal Thermodynamics of a Unitary Fermi Gas journal January 2012
Number of closed-channel molecules in the BEC-BCS crossover journal February 2009
The pseudogap regime in the unitary Fermi gas journal March 2019
Neutron Matter from Low to High Density journal October 2015
Static structure factor of a strongly correlated Fermi gas at large momenta journal July 2010
Molecular signatures in the structure factor of an interacting Fermi gas journal September 2006
Making, probing and understanding ultracold Fermi gases journal July 2008

Cited By (3)


Similar Records

Pairing Correlations across the Superfluid Phase Transition in the Unitary Fermi Gas
Journal Article · Sun Mar 01 19:00:00 EST 2020 · Physical Review Letters · OSTI ID:1799991

The pseudogap regime in the unitary Fermi gas
Journal Article · Mon Mar 04 19:00:00 EST 2019 · European Physical Journal. Special Topics · OSTI ID:1530857

Reducing the complexity of finite-temperature auxiliary-field quantum Monte Carlo
Journal Article · Tue Mar 16 20:00:00 EDT 2021 · Computer Physics Communications · OSTI ID:1849345