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Related papers: Pairing from repulsion in a two-dimensional Fermi …

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We implement an explicit two-loop calculation of the coupling functions and the self-energy of interacting fermions with a two-dimensional flat Fermi surface in the framework of the field theoretical renormalization group (RG) approach.…

Strongly Correlated Electrons · Physics 2009-11-10 H. Freire , E. Correa , A. Ferraz

A free Fermi gas has, famously, a superconducting susceptibility that diverges logarithmically at zero temperature. In this paper we ask whether this is still true for a Fermi liquid and find that the answer is that it does {\it not}. From…

Strongly Correlated Electrons · Physics 2010-12-20 S. A. Parameswaran , R. Shankar , S. L. Sondhi

We analyze when a repulsively interacting two-component Fermi gas becomes thermodynamically unstable against phase separation. We focus on the strongly polarised limit where the free energy of the homogeneous mixture can be calculated…

Quantum Gases · Physics 2013-06-13 Pietro Massignan , Zhenhua Yu , Georg M. Bruun

This work present a new class of variational wave functions for fermi systems in any dimension. These wave functions introduce correlations between Cooper pairs in different momentum states and the relevant correlations can be computed…

Superconductivity · Physics 2009-10-31 B Sriram Shastry

We investigate strong-coupling properties of a two-dimensional ultracold Fermi gas in the normal state. Including pairing fluctuations within the framework of a $T$-matrix approximation, we calculate the distribution function…

Quantum Gases · Physics 2016-01-27 M. Matsumoto , D. Inotani , Y. Ohashi

Using a combination of results from exact mappings and from mean-field theory we explore the phase diagram of quasi-one-dimensional systems of identical fermions with attractive dipolar interactions. We demonstrate that at low density these…

Quantum Gases · Physics 2013-09-12 F. Deuretzbacher , G. M. Bruun , C. J. Pethick , M. Jona-Lasinio , S. M. Reimann , L. Santos

We address the problem of computing the thermodynamic properties of the repulsive one-dimensional two-component Fermi gas with contact interaction, also known as the Gaudin-Yang model. Using a specific lattice embedding and the quantum…

Quantum Gases · Physics 2016-03-23 Ovidiu I. Patu , Andreas Klumper

Fermion systems with flat bands can boost superconductivity by enhancing the density of states at the Fermi level. We use quasiexact numerical methods to show that repulsive interactions between spinless fermions in a one-dimensional (1D)…

Strongly Correlated Electrons · Physics 2022-10-12 Iman Mahyaeh , Thomas Köhler , Annica M. Black-Schaffer , Adrian Kantian

We theoretically study the normal phase properties of strongly interacting two-component Fermi gases in two spatial dimensions. In the limit of weak attraction, we find that the gas can be described in terms of effective polarons. As the…

Quantum Gases · Physics 2012-08-07 Ville Pietilä

We study a two-dimensional two-component Fermi gas with attractive or repulsive short-range interactions at zero temperature. We use Diffusion Monte Carlo with Fixed Node approximation in order to calculate the energy per particle and the…

Quantum Gases · Physics 2013-03-18 Gianluca Bertaina

Pairing of fermions is ubiquitous in nature and it is responsible for a large variety of fascinating phenomena like superconductivity, superfluidity of $^3$He, the anomalous rotation of neutron stars, and the BEC-BCS crossover in strongly…

Quantum Gases · Physics 2011-12-02 Michael Feld , Bernd Fröhlich , Enrico Vogt , Marco Koschorreck , Michael Köhl

We develop a non-Hermitian effective theory for a repulsively interacting Fermi gas in the excited branch. The on-shell $T$-matrix is employed as a complex-valued interaction term, which describes a repulsive interaction between atoms in…

Quantum Gases · Physics 2021-01-14 Hiroyuki Tajima , Kei Iida

We theoretically investigate the polaron physics of an impurity immersed in a two-dimensional Fermi sea, interacting via a p-wave interaction at finite temperature. In the unitary limit with a divergent scattering area, we find a…

Quantum Gases · Physics 2023-11-20 Hui Hu , Jia Wang , Xia-Ji Liu

We employ radio-frequency spectroscopy to investigate a polarized spin-mixture of ultracold ${}^6$Li atoms close to a broad Feshbach scattering resonance. Focusing on the regime of strong repulsive interactions, we observe well-defined…

Fermi gases with repulsive interactions are characterized by measuring their compressibility as a function of interaction strength. The compressibility is obtained from in-trap density distributions monitored by phase contrast imaging. For…

Spatial profiles of the pressure have been measured in atomic Fermi gases with primarily 2D kinematics. The in-plane motion of the particles is confined by a gaussian-shape potential. The two-component deeply-degenerate Fermi gases are…

Quantum Gases · Physics 2016-09-05 Kirill Martiyanov , Tatiana Barmashova , Vasiliy Makhalov , Andrey Turlapov

We prove that the weak coupling 2D Hubbard model away from half filling is a Landau Fermi liquid up to exponentially small temperatures. In particular we show that the wave function renormalization is an order 1 constant and essentially…

Strongly Correlated Electrons · Physics 2011-10-18 G. Benfatto , A. Giuliani , V. Mastropietro

We consider a mixture of two neutral cold Fermi gases with repulsive interactions. We show that in some region of the parameter space of the system the effective attraction between fermions of the same type can appear due to the exchange of…

Quantum Gases · Physics 2013-08-01 T. Espinosa-Ortega , O. Kyriienko , I. A. Shelykh

In this work we theoretically study pairing in two-dimensional Fermi gases, a system which is experimentally accessible using cold atoms. We start by deriving the mean-field pairing gap equation for a coordinate-space potential with a…

Quantum Gases · Physics 2020-03-04 Tash Zielinski , Bernard Ross , Alexandros Gezerlis

Pairing is the fundamental requirement for fermionic superfluidity and superconductivity. To understand the mechanism behind pair formation is an ongoing challenge in the study of many strongly correlated fermionic systems. Cooper pairs are…