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We discuss ultra-cold Fermi gases in two dimensions, which could be realized in a strongly confining one-dimensional optical lattice. We obtain the temperature versus effective interaction phase diagram for an s-wave superfluid and show…

Other Condensed Matter · Physics 2015-06-25 S. S. Botelho , C. A. R. Sa de Melo

Electrons interact strongly with their environment. The result of these interactions is, most of the time, encoded in an effective mass. In non-relativistic systems, as in condensed matter, the electrons plus interactions form a…

Strongly Correlated Electrons · Physics 2021-06-16 Heron Caldas

We show that the minimal mean-field theory to use for calculating the pair distribution functions $g_{\sigma\sigma'}(\vec{r},\vec{r}\,')$ of a spatially homogeneous, unpolarized spin-1/2 superfluid Fermi gas is not the ordinary static BCS…

Quantum Gases · Physics 2026-04-22 Yvan Castin

In the study of strongly interacting systems, correlations on the two-particle level are receiving more and more attention. In this work, we study a particular two-particle correlation function: the fermion-boson vertex. It describes the…

The viscous and thermal relaxation rates of an interacting fermion gas are calculated as functions of temperature and scattering length, using a many-body scattering matrix which incorporates medium effects due to Fermi blocking of…

Statistical Mechanics · Physics 2009-11-11 G. M. Bruun , H. Smith

In this letter we consider $D$-dimensional interacting Fermi liquids, and demonstrate that an attractive interaction with a finite range $R_s$ that is much greater than the Fermi wavelength $\lambda_F$ breaks the conventional BCS theory of…

Strongly Correlated Electrons · Physics 2025-02-18 Dmitry Miserev , Joel Hutchinson , Herbert Schoeller , Jelena Klinovaja , Daniel Loss

We consider a very asymmetric system of Fermions with an interaction characterized by a positive scattering length only. The minority atoms pair and form a BEC of dimers, while the surplus fermions interact only indirectly through the…

Statistical Mechanics · Physics 2009-05-15 Aurel Bulgac , Sukjin Yoon

Cross sections are calculated for neutrino scattering off heavy nuclei at energies below 50 MeV. The theory of Fermi liquid is applied to estimate the rate of neutrino-nucleon elastic and inelastic scattering in a nuclear medium in terms of…

Nuclear Theory · Physics 2008-11-26 Gennady I. Lykasov , Vadim A. Bednyakov

We calculate the effects of induced interactions on the transition temperature to the BCS state in dilute Fermi gases. For a pure Fermi system with 2 species having equal densities, the transition temperature is suppressed by a factor…

Condensed Matter · Physics 2009-10-31 H. Heiselberg , C. J. Pethick , H. Smith , L. Viverit

The BCS-to-BEC crossover, as well as the nature of Cooper pairs, in a superconducting and Fermi superfluid medium is studied from the exact ground state wavefunction of the reduced BCS Hamiltonian. As the strength of the interaction…

Superconductivity · Physics 2009-11-11 Gerardo Ortiz , Jorge Dukelsky

From an extensive calculation of static properties of a trapped Fermi superfluid at zero temperature using a density-functional formulation, we demonstrate a universal behavior of its observables, such as energy, chemical potential, radius…

Other Condensed Matter · Physics 2009-11-13 S. K. Adhikari

We study a trapped system of fermions with a zero-range two-body interaction using the shell-model Monte Carlo method, providing {\em ab initio} results for the low particle number limit where mean-field theory is not applicable. We present…

Superconductivity · Physics 2009-09-22 N. T. Zinner , K. Mølmer , C. Özen , D. J. Dean , K. Langanke

We investigate many-body phase diagrams of atomic boson-fermion mixtures loaded in the two-dimensional optical lattice. Bosons mediate an attractive, finite-range interaction between fermions, leading to fermion pairing phases of different…

Superconductivity · Physics 2007-05-23 D. -W. Wang , M. D. Lukin , E. Demler

A two-dimensional (2D) assembly of noninteracting, temperature-dependent, composite-boson Cooper pairs (CPs) in chemical and thermal equilibrium with unpaired fermions is examined in a binary boson-fermion statistical model as the…

Superconductivity · Physics 2016-08-16 M. Casas , N. J. Davidson , M. de Llano , T. A. Mamedov , A. Puente , R. M. Quick , A. Rigo , M. A. Solís

By using a well established 'ab initio' theoretical approach developed in the past to quantitatively study the superconductivity of condensed matter systems, which is based on the Kohn-Sham Density Functional theory, I study the superfluid…

Quantum Gases · Physics 2016-06-01 Francesco Ancilotto

Understanding how strongly correlated two-dimensional (2D) systems can give rise to unconventional superconductivity with high critical temperatures is one of the major unsolved problems in condensed matter physics. Ultracold 2D Fermi gases…

Quantum Gases · Physics 2021-06-09 Lennart Sobirey , Niclas Luick , Markus Bohlen , Hauke Biss , Henning Moritz , Thomas Lompe

A two-dimensional (2D) assembly of noninteracting, temperature-dependent, composite-boson Cooper pairs (CPs) in chemical and thermal equilibrium with unpaired fermions is examined in a binary boson-fermion statistical model as the…

Superconductivity · Physics 2016-08-15 M. Casas , N. J. Davidson , M. de Llano , T. A. Mamedov , A. Puente , R. M. Quick , A. Rigo , M. A. Solís

The BCS-BEC crossover realized experimentally with ultra-cold Fermi gases may be considered as one of the important scientific achievements occurred during the last several years. The flexibility for operating on these systems on the…

Quantum Gases · Physics 2024-03-20 Giancarlo Calvanese Strinati

A density functional theory is proposed for strongly interacting fermions with arbitrary large negative scattering length. The functional has only two parameters that are directly fixed to reproduce the universal properties of unitary gas:…

Nuclear Theory · Physics 2016-11-03 Denis Lacroix

We have studied, in a fully non-perturbative calculation, a dilute system of spin 1/2 interacting fermions, characterized by an infinite scattering length at finite temperatures. Various thermodynamic properties and the condensate fraction…

Statistical Mechanics · Physics 2014-10-13 Aurel Bulgac , Joaquin E. Drut , Piotr Magierski