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Related papers: Auxiliary field formalism for dilute fermionic ato…

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In this work, we describe the dynamics of a Bose-Einstein condensate interacting with a degenerate Fermi gas, at zero temperature. First, we analyze the mean-field approximation of the many-body Schr\"odinger dynamics and prove emergence of…

Mathematical Physics · Physics 2025-07-04 Esteban Cárdenas , Joseph K. Miller , Nataša Pavlović

We study ultracold superfluid Bose-Fermi mixtures in three dimensions, with stronger confinement along one or two directions, using a non-perturbative beyond-mean-field model for bulk chemical potential valid along the weak-coupling to…

Quantum Gases · Physics 2023-08-29 Pardeep Kaur , Sandeep Gautam , S. K. Adhikari

We discuss an integrable model of interacting Fermions in one dimension, that allows an exact description of the crossover from a BCS- to a Bose-like superfluid. This model bridges the Gaudin-Yang model of attractive spin 1/2 Fermions to…

Statistical Mechanics · Physics 2007-05-23 J. N. Fuchs , A. Recati , W. Zwerger

We investigate the impact of higher-order fermionic deformations in phase transitions analogous to those described by the Bardeen-Cooper-Schrieffer (BCS) theory. Focusing specifically on the 8-fermion interaction, we show that this term can…

Superconductivity · Physics 2026-03-18 Diego Rodriguez-Gomez , Jorge G. Russo

A gas of interacting ultracold fermions can be tuned into a strongly interacting regime using a Feshbach resonance. Here we theoretically study quasiparticle transport in a system of two reservoirs of interacting ultracold fermions on the…

Quantum Gases · Physics 2016-09-19 Tibor Sekera , Christoph Bruder , Wolfgang Belzig

Using a functional renormalization group approach we study the zero temperature phase diagram of two-dimensional Bose-Fermi mixtures of ultra-cold atoms in optical lattices, in the limit when the velocity of bosonic condensate fluctuations…

Other Condensed Matter · Physics 2007-10-30 L. Mathey , S-W. Tsai , A. H. Castro Neto

The Quantum Monte Carlo method for spin 1/2 fermions at finite temperature is formulated for dilute systems with an s-wave interaction. The motivation and the formalism are discussed along with descriptions of the algorithm and various…

Statistical Mechanics · Physics 2009-02-05 Aurel Bulgac , Joaquin E. Drut , Piotr Magierski

We consider a mixture of a spin-polarized Fermi gas and a dipolar Bose-Einstein condensate in which s-wave scattering between fermions and the quasiparticles of the dipolar condensate can result in an effective attractive Fermi-Fermi…

Quantum Gases · Physics 2015-06-03 Ben Kain , Hong Y. Ling

We study s-wave pairing of population imbalanced Fermi atoms in quasi two dimensions using a mean field theory. At zero temperature, we map out the phase diagram in the entire Bardeen, Cooper and Schrieffer-Bose Einstein condensation…

Other Condensed Matter · Physics 2009-08-03 Theja N. De Silva

We determine the phase diagram of strongly correlated fermions in the crossover from Bose-Einstein condensates of molecules (BEC) to Cooper pairs of fermions (BCS) utilizing an artificial neural network. By applying advanced image…

Quantum Gases · Physics 2023-10-25 M. Link , K. Gao , A. Kell , M. Breyer , D. Eberz , B. Rauf , M. Köhl

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

The functional renormalisation group is used for the BCS-BEC crossover in gases of ultracold fermionic atoms. In a simple truncation, we see how universality and an effective theory with composite bosonic di-atom states emerge. We obtain a…

Superconductivity · Physics 2009-11-13 S. Diehl , H. Gies , J. M. Pawlowski , C. Wetterich

We discuss the possibility of a quantum phase transition in ultracold spin polarized fermionic gases which exhibit a p-wave Feshbach resonace. We show that when fermionic atoms form a condensate that can be externally tuned between the BCS…

Strongly Correlated Electrons · Physics 2016-08-16 S. S. Botelho , C. A. R. Sá de Melo

The zero-temperature properties of a dilute two-component Fermi gas in the BCS-BEC crossover are investigated. On the basis of a generalization of the variational Schwinger method, we construct approximate semi-analytical formulae for…

Statistical Mechanics · Physics 2016-08-31 Yeong E. Kim , Alexander L. Zubarev

We present a theoretical study of the BEC-BCS crossover in the Bose-Einstein-Condensate regime (BEC), in the case of an unequal number of fermions of two species. We take full account of the composite nature of the dimers made of fermions.…

Quantum Gases · Physics 2015-05-14 F. Alzetto , X. Leyronas

We study low temperature properties of atomic gases in trimerized optical kagom\'{e} lattices. The laser arrangements that can be used to create these lattices are briefly described. We also present explicit results for the coupling…

Other Condensed Matter · Physics 2009-11-11 B. Damski , H. Fehrmann , H. -U. Everts , M. Baranov , L. Santos , M. Lewenstein

We present a theory for a superfluid Fermi gas near the BCS-BEC crossover, including pairing fluctuation contributions to the free energy similar to that considered by Nozieres and Schmitt-Rink for the normal phase. In the strong coupling…

Superconductivity · Physics 2007-05-23 Hui Hu , Xia-Ji Liu , Peter D. Drummond

We show that a dilute atomic Fermi system at sufficiently low temperatures, can display fermionic superfluidity, even in the case of a repulsive atom-atom interaction, when the scattering length is positive. The attraction leading to the…

Statistical Mechanics · Physics 2007-05-23 Aurel Bulgac , Paulo F. Bedaque , Antonio C. Fonseca

We derive a theoretical description for dilute Bose gases as a loop expansion in terms of composite-field propagators by rewriting the Lagrangian in terms of auxiliary fields related to the normal and anomalous densities. We demonstrate…

Quantum Gases · Physics 2010-12-28 Fred Cooper , Chih-Chun Chien , Bogdan Mihaila , John F. Dawson , Eddy Timmermans

The low-energy modes of a spin-imbalanced superfluid Fermi gas in the Bardeen-Cooper-Schrieffer (BCS) side are studied. The gas is assumed to be sufficiently dilute so that the pairing of atoms can be considered effective only in s-wave…

Quantum Gases · Physics 2017-12-06 F. Matera , M. F. Wagner