Pressure, Compressibility, and Contact of the Two-Dimensional Attractive Fermi Gas

Anderson, E. R.; Drut, Joaquín E.

doi:10.1103/physrevlett.115.115301

Cited by 82 publications

(119 citation statements)

References 70 publications

(53 reference statements)

Supporting

Mentioning

109

Contrasting

Unclassified

Order By: Relevance

“…1 the results for the pressure and density equations of state at interaction strength βε B = 0.5 with Q = 0, compared with the predictions from the mean-field theory, above T c calculations with the self-consistent Luttinger-Ward theory [41,44] and lattice QMC simulation [46], and with recent experimental measurements [32]. It is reasonable from the comparison of results in Fig.…”

supporting

confidence: 66%

See 1 more Smart Citation

Superfluid density and critical velocity near the Berezinskii-Kosterlitz-Thouless transition in a two-dimensional strongly interacting Fermi gas

Mulkerin

Dyke

et al. 2017

Phys. Rev. A

View full text Add to dashboard Cite

We theoretically investigate superfluidity in a strongly interacting Fermi gas confined to two dimensions at finite temperature. Using a Gaussian pair fluctuation theory in the superfluid phase, we calculate the superfluid density and determine the critical temperature and chemical potential at the Berezinskii-Kosterlitz-Thouless transition. We propose that the transition can be unambiguously demonstrated in cold-atom experiments by stirring the superfluid Fermi gas using a red detuned laser beam, to identify the characteristic jump in the local Landau critical velocity at the superfluidnormal interface, as the laser beam moves across the cloud.PACS numbers: 03.75. Ss, 03.70.+k, 05.70.Fh, 03.65.Yz In two-dimensional (2D) many-body systems, topologically nontrivial vortex fluctuations, that are suppressed due to vortex/anti-vortex binding at low temperature, become amplified above a certain critical temperature, leading to the so-called Berezinskii-Kosterlitz-Thouless (BKT) transition [1][2][3]. The BKT transition has been of great importance in different branches of physics and has been observed in a range of settings [4][5][6][7]. In particular, ultracold atomic gases are an ideal candidate to understand the interaction-driven BKT physics [7], owing to the unprecedented controllability over interatomic interactions, dimensionality and species [8]. Over the past decade, the BKT transition in a 2D weakly interacting Bose gas has been extensively studied by measuring the phase coherence [7,9], confirming the universal equation of state [10,11], probing the superfluidity [12], or observing the free vortex proliferation [7,13,14].A 2D interacting Fermi gas at the crossover from a Bose-Einstein condensate (BEC) to a Bardeen-CooperSchrieffer (BCS) superfluid provides a unique platform to address the universal BKT mechanism [15,16], since the underlying character of the system changes from tightly bound composite bosons to loosely bound Cooper pairs of fermions, with decreasing attractions [17]. Indeed, the fermionic BKT transition is now being pursued by several cold-atom laboratories [18][19][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35], and there are indications of the transition from the measurements of pair condensation and correlation function, where: (i) the center-of-mass momentum distribution of Cooper pairs, n Q , exhibits anomalous enhancement near Q = 0 below a certain temperature [28], and (ii) the first-order correlation function g 1 (r) in real space decays algebraically [29]. However, confirmation of the transition is still to be demonstrated, as these two features may be explained using a strong-coupling theory in the normal phase [36]. This situation marks the importance of having accurate theoretical predictions for the fermionic BKT transition.The purpose of this Letter is to apply a strong-coupling theory, beyond mean-field, to a 2D interacting Fermi gas in the superfluid phase and present semi-quantitative predictions for the BKT critical chemical potential, critical temperat...

show abstract

supporting

confidence: 66%

“…The density n of the system can be calculated [41,44] and lattice QMC simulation (blue squares) [46], and the experimental data from Swinburne [32] (solid circles with error bar at a slightly smaller βεB = 0.47).…”

mentioning

confidence: 99%

Superfluid density and critical velocity near the Berezinskii-Kosterlitz-Thouless transition in a two-dimensional strongly interacting Fermi gas

Mulkerin

Dyke

et al. 2017

Phys. Rev. A

View full text Add to dashboard Cite

show abstract

“…Studies at finite temperature have also appeared (see e.g. [35][36][37][38][39][40][41][42][43][44]). …”

Section: Introductionmentioning

confidence: 99%

Ground state of the two-dimensional attractive Fermi gas: Essential properties from few to many body

2016

View full text Add to dashboard Cite

We calculate the ground-state properties of unpolarized two-dimensional attractive fermions in the range from few to many particles. Using first-principles lattice Monte Carlo methods, we determine the ground-state energy, Tan's contact, momentum distribution, and single-particle correlation function. We investigate those properties for systems of N = 4, 8, ..., 40 particles and for a wide range of attractive couplings. As the attractive coupling is increased, the thermodynamic limit is reached at progressively lower N due to the dominance of the two-body sector. At large momenta k, the momentum distribution displays the expected k −4 behavior, but its onset shifts from k ≃ 1.8k F at weak coupling towards higher k at strong coupling.

show abstract

“…A rich area of study subject to ongoing investigation is that of low dimensionality [16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38]. These dilute cold atomic gases have been trapped using anisotropic potentials, resulting in a quasi-2D pancake-shape gas cloud.…”

Section: Introductionmentioning

confidence: 99%

Fermions in Two Dimensions: Scattering and Many-Body Properties

et al. 2017

View full text Add to dashboard Cite

Ultracold atomic Fermi gases in two-dimensions (2D) are an increasingly popular topic of research. The interaction strength between spin-up and spindown particles in two-component Fermi gases can be tuned in experiments, allowing for a strongly interacting regime where the gas properties are yet to be fully understood. We have probed this regime for 2D Fermi gases by performing T = 0 ab initio diffusion Monte Carlo (DMC) calculations. The many-body dynamics are largely dependent on the two-body interactions, therefore we start with an in-depth look at scattering theory in 2D. We show the partial-wave expansion and its relation to the scattering length and effective range. Then we discuss our numerical methods for determining these scattering parameters. We close out this discussion by illustrating the details of bound states in 2D. Transitioning to the many-body system, we use variationally optimized wave functions to calculate ground-state properties of the gas over a range of interaction strengths. We show results for the energy per particle and parametrize an equation of state. We then proceed to determine the chemical potential for the strongly interacting gas.

show abstract

Pressure, Compressibility, and Contact of the Two-Dimensional Attractive Fermi Gas

Cited by 82 publications

References 70 publications

Superfluid density and critical velocity near the Berezinskii-Kosterlitz-Thouless transition in a two-dimensional strongly interacting Fermi gas

Superfluid density and critical velocity near the Berezinskii-Kosterlitz-Thouless transition in a two-dimensional strongly interacting Fermi gas

Ground state of the two-dimensional attractive Fermi gas: Essential properties from few to many body

Fermions in Two Dimensions: Scattering and Many-Body Properties

Contact Info

Product

Resources

About