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Related papers: Pseudo-gap pairing in ultracold Fermi atoms

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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

The superfluid, pair condensed spin-1/2 Fermi gases are supposed to exhibit at nonzero wave vector a still unobserved collective excitation mode in their pair-breaking continuum. Using BCS theory at zero temperature and in the long…

Quantum Gases · Physics 2021-01-11 Yvan Castin

We investigate magnetic properties and effects of pairing fluctuations in the BCS (Bardeen-Cooper-Schrieffer)-BEC (Bose-Einstein condensation) crossover regime of an ultracold Fermi gas. Recently, Liu and Hu, and Parish, pointed out that…

Quantum Gases · Physics 2015-06-11 Takashi Kashimura , Ryota Watanabe , Yoji Ohashi

We report results of quantum Monte Carlo calculations of the ground state of dilute Fermi gases with attractive short range two-body interactions. The strength of the interaction is varied to study different pairing regimes which are…

Atomic Physics · Physics 2009-02-05 S. Y. Chang , J. Carlson , V. R. Pandharipande , K. E. Schmidt

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 present a comprehensive study of the Bose-Einstein condensate to Bardeen-Cooper-Schrieffer (BEC-BCS) crossover in fermionic $^6$Li using Bragg spectroscopy. A smooth transition from molecular to atomic spectra is observed with a clear…

Other Condensed Matter · Physics 2008-12-22 G. Veeravalli , E. Kuhnle , P. Dyke , C. J. Vale

We investigate magnetic properties and strong coupling corrections in the BCS (Bardeen-Cooper-Schrieffer)-BEC (Bose-Einstein condensation) crossover regime of an ultracold Fermi gas. Within the framework of an extended $T$-matrix theory, we…

Quantum Gases · Physics 2015-10-16 Hiroyuki Tajima , Ryo Hanai , Ryota Watanabe , Yoji Ohashi

We investigate pseudogap phenomena in the unitarity limit of a trapped superfluid Fermi gas. Including effect of strong pairing fluctuations within a $T$-matrix approximation, as well as effects of a harmonic trap within the local density…

Quantum Gases · Physics 2015-05-28 Ryota Watanabe , Shunji Tsuchiya , Yoji Ohashi

We present a theoretical review of the recent progress in nonequilibrium BCS (Bardeen-Cooper-Schrieffer)-BEC (Bose-Einstein condensation) crossover physics. As a paradigmatic example, we consider a strongly interacting driven-dissipative…

Quantum Gases · Physics 2025-03-07 Taira Kawamura , Yoji Ohashi

We address the thermodynamics, density profiles and superfluid density of trapped fermions undergoing BCS-BEC crossover, with and without population imbalance. Our approach represents a fully consistent treatment of "pseudogap effects",…

Strongly Correlated Electrons · Physics 2011-09-13 Yan He , Chih-Chun Chien , Qijin Chen , K. Levin

We consider trapped atomic Fermi gases with Feshbach-resonance enhanced interactions in pseudogap and superfluid temperatures. We calculate the spectrum of RF(or laser)-excitations for transitions that transfer atoms out of the superfluid…

Superconductivity · Physics 2016-08-31 J. Kinnunen , M. Rodriguez , P. Torma

Conventional superconductivity follows Bardeen-Cooper-Schrieffer(BCS) theory of electrons-pairing in momentum-space, while superfluidity is the Bose-Einstein condensation(BEC) of atoms paired in real-space. These properties of solid metals…

We observe many-body pairing in a two-dimensional gas of ultracold fermionic atoms at temperatures far above the critical temperature for superfluidity. For this, we use spatially resolved radio-frequency spectroscopy to measure pairing…

I present a simple analytical model describing the normal state of a superconductor with a pseudogap in the density of states, such as in underdoped cuprates. In nearly two-dimensional systems, where the superconducting transition…

Superconductivity · Physics 2009-10-30 O. Tchernyshyov

We experimentally determined various thermodynamic quantities of interacting two-component fermions at the zero-temperature limit from the Bardeen-Cooper-Schrieffer (BCS) region to the unitarity limit. The obtained results are very accurate…

This chapter presents the crossover from the Bardeen-Cooper-Schrieffer (BCS) state of weakly-correlated pairs of fermions to the Bose-Einstein condensation (BEC) of diatomic molecules in the atomic Fermi gas. Our aim is to provide a…

Quantum Gases · Physics 2017-08-23 Meera M. Parish

Pseudogap is a ubiquitous phenomenon in strongly correlated systems such as high-$T_{\rm c}$ superconductors, ultracold atoms and nuclear physics. While pairing fluctuations inducing the pseudogap are known to be enhanced in low-dimensional…

Quantum Gases · Physics 2020-09-23 Hiroyuki Tajima , Shoichiro Tsutsui , Takahiro M. Doi

We study the superfluid behavior of ultracold atomic Fermi gases with a short range attractive interaction in a two-dimensional optical lattice (2DOL) using a pairing fluctuation theory, within the context of BCS-BEC crossover. We find that…

Quantum Gases · Physics 2022-03-01 Lin Sun , Jibiao Wang , Xiang Chu , Qijin Chen

Wave-vector resolved radio frequency (rf) spectroscopy data for an ultracold trapped Fermi gas are reported for several couplings at Tc, and extensively analyzed in terms of a pairing-fluctuation theory. We map the evolution of a strongly…

The ground-state superfluid behavior of ultracold atomic Fermi gases with a short-range attractive interaction in a quasi-two-dimensional Lieb lattice is studied using BCS mean-field theory, within the context of BCS-BEC crossover. We find…

Quantum Gases · Physics 2024-03-27 Hao Deng , Chuping Li , Yuxuan Wu , Lin Sun , Qijin Chen
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