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Related papers: BCS-BEC crossover in a quasi-two-dimensional Fermi…

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We consider the two-dimensional Fermi gas at finite temperature with attractive short-range interactions. Using the virial expansion, which provides a controlled approach at high temperatures, we determine the spectral function and contact…

Quantum Gases · Physics 2014-01-08 V. Ngampruetikorn , J. Levinsen , Meera M. Parish

We demonstrate that the theoretical description of current experiments of quasi-2D Fermi gases requires going beyond usual 2D theories. We provide such a theory for the highly spin-imbalanced quasi-2D Fermi gas. For typical experimental…

Quantum Gases · Physics 2012-10-12 Jesper Levinsen , Stefan K. Baur

A two-dimensional (2D) harmonically trapped interacting Fermi gas is anticipated to exhibit a quantum anomaly and possesses a breathing mode at frequencies different from a classical scale invariant value $\omega_{B}=2\omega_{\perp}$, where…

Quantum Gases · Physics 2019-02-27 Hui Hu , Brendan C. Mulkerin , Umberto Toniolo , Lianyi He , Xia-Ji Liu

We investigate pseudogap phenomena originating from pairing fluctuations in the BCS-BEC crossover regime of a two-dimensional Fermi gas in a harmonic trap. Including pairing fluctuations within a $T$-matrix theory and effects of a trap…

Quantum Gases · Physics 2015-06-05 Ryota Watanabe , Shunji Tsuchiya , Yoji Ohashi

In a trapped atomic Fermi gas, one can tune continuously via a Feshbach resonance the effective pairing interaction between fermionic atoms from very weak to very strong. As a consequence, the low temperature superfluidity evolves…

Quantum Gases · Physics 2011-01-17 Yi Yu , Qijin Chen

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

This paper addresses the transition from the normal to the superfluid state in strongly correlated two dimensional fermionic superconductors and Fermi gases. We arrive at the Berezinskii-Kosterlitz-Thouless (BKT) temperature…

Superconductivity · Physics 2020-07-13 Xiaoyu Wang , Qijin Chen , K. Levin

We investigate the density profiles of a partially polarized trapped Fermi gas in the BCS-BEC crossover region using mean field theory within the local density approximation. Within this approximation the gas is phase separated into…

Other Condensed Matter · Physics 2007-05-23 Theja N. De Silva , Erich J. Mueller

One of the challenging goals in the studies of many-body physics with ultracold atoms is the creation of a topological $p_{x} + ip_{y}$ superfluid for identical fermions in two dimensions (2D). The expectations of reaching the critical…

Quantum Gases · Physics 2017-12-05 M. A. Caracanhas , F. Schreck , C. Morais Smith

We investigate a two-species Fermi gas with a large mass ratio interacting by an interspecies short-range interaction. Using the Born-Oppenheimer approximation, we determine the interaction energy of two heavy fermions immersed in the Fermi…

Other Condensed Matter · Physics 2009-02-05 Yusuke Nishida

The BCS-BEC crossover is studied in a systematic way in the broken-symmetry phase between zero temperature and the critical temperature. This study bridges two regimes where quantum and thermal fluctuations are, respectively, important. The…

Superconductivity · Physics 2007-05-23 P. Pieri , L. Pisani , G. C. Strinati

We show the emergence of a strongly interacting Bose-Fermi mixture from a two-component Fermi mixture with population imbalance. By analyzing in situ density profiles of $^6$Li atoms in the BCS-BEC crossover regime we identify a critical…

Statistical Mechanics · Physics 2009-11-13 Yong-il Shin , André Schirotzek , Christian H. Schunck , Wolfgang Ketterle

We perform a variational quantum Monte Carlo simulation of the transition from a Bardeen-Cooper-Schrieffer superfluid (BCS) to a Bose-Einstein condensate (BEC) at zero temperature. The model Hamiltonian involves an attractive short range…

Other Condensed Matter · Physics 2008-12-01 R. Jauregui , R. Paredes , L. Rosales-Zarate , G. Toledo Sanchez

We study equilibrium properties of a cold two-component Fermi gas confined in a quasi-one-dimensional trap of the transverse size $l_{\perp}$. In the dilute limit ($nl_{\perp}\ll 1$, where $n$ is the 1D density) the problem is exactly…

Other Condensed Matter · Physics 2009-11-10 I. V. Tokatly

We investigate the superfluid transition temperature of quasi-two-dimensional imbalanced Fermi gases beyond the mean-field approximation, through the second-order (or induced) interaction effects. For a balanced Fermi system the transition…

Quantum Gases · Physics 2015-06-11 M. A. Resende , A. L. Mota , R. L. S. Farias , Heron Caldas

We study the BCS-BEC crossover in the strongly correlated regime of an ultra-cold rotating two component Fermi gas. Strong correlations are shown to generate an additional long-range interaction which results in a modified crossover region…

Mesoscale and Nanoscale Physics · Physics 2007-10-30 S. G. Bhongale , M. R. Goosen , S. J. J. M. F. Kokkelmans

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

We present an overview of our recent measurements on the crossover from a Bose-Einstein condensate of molecules to a Bardeen-Cooper-Schrieffer superfluid. The experiments are performed on a two-component spin-mixture of $^6$Li atoms, where…

Other Condensed Matter · Physics 2009-11-10 M. Bartenstein , A. Altmeyer , S. Riedl , S. Jochim , R. Geursen , C. Chin , J. Hecker Denschlag , R. Grimm

We measure excitation spectra of an ultracold gas of fermionic $^{40}$K atoms in the BCS-BEC crossover regime. The measurements are performed with a novel spectroscopy that employs a small modulation of the B-field close to a Feshbach…

Statistical Mechanics · Physics 2011-08-12 Markus Greiner , Cindy A. Regal , Deborah S. Jin

We explore the evolution of a ultracold quantum gas of interacting fermions crossing from a Bardeen-Cooper-Schrieffer (BCS) superfluidity to a Bose-Einstein condensation (BEC) of molecular bosons in the presence of a tunable-range…

Quantum Gases · Physics 2019-11-12 Davide Giambastiani , Michele Barsanti , Maria Luisa Chiofalo