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Related papers: Density and spin response functions in ultracold f…

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We propose to utilize density-density correlations in the image of an expanding gas cloud to probe complex many body states of trapped ultra-cold atoms. In particular we show how this technique can be used to detect superfluidity of…

Soft Condensed Matter · Physics 2009-11-10 Ehud Altman , Eugene Demler , Mikhail D. Lukin

The method of functional renormalization is applied to the theoretical investigation of ultracold quantum gases. Flow equations are derived for a Bose gas with approximately pointlike interaction, for a Fermi gas with two (hyperfine) spin…

Quantum Gases · Physics 2015-05-14 S. Floerchinger

We investigate strong-coupling superfluidity in a uniform gas of Fermi atoms attractively interacting via quasi-molecular bosons associated with a Feshbach resonance. This interaction is tunable by the threshold energy $2\nu$ of the…

Soft Condensed Matter · Physics 2009-11-10 Y. Ohashi , A. Griffin

We study the dynamic structure factor for density and spin within the crossover from BCS superfluidity of atomic fermions to the Bose-Einstein condensation of molecules. Both structure factors are experimentally accessible via Bragg…

Statistical Mechanics · Physics 2009-11-10 H. P. Büchler , P. Zoller , W. Zwerger

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

Fermionic many-body systems provide an unrivaled arena to investigate how interactions drive the emergence of collective quantum behavior, such as macroscopic coherence and superfluidity. Central to these phenomena is the formation of…

We theoretically investigate the uniform spin susceptibility $\chi$ in the superfluid phase of an ultracold Fermi gas in the BCS (Bardeen-Cooper-Schrieffer)-BEC (Bose-Einstein condensation) crossover region. In our previous paper [H.…

Quantum Gases · Physics 2016-01-20 H. Tajima , R. Hanai , Y. Ohashi

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

Strongly Correlated Electrons · Physics 2009-11-11 S. S. Botelho , C. A. R. Sa de Melo

Quantum-degenerate Fermi gases provide a remarkable opportunity to study strongly interacting fermions. In contrast to other Fermi systems, such as superconductors, neutron stars or the quark-gluon plasma, these gases have low densities and…

Superconductivity · Physics 2007-05-23 M. W. Zwierlein , J. R. Abo-Shaeer , A. Schirotzek , C. H. Schunck , W. Ketterle

We investigate the crossover from Bardeen-Cooper-Schrieffer (BCS) superfluidity to Bose-Einstein condensation (BEC) in a two-dimensional Fermi gas at T=0 using the fixed-node diffusion Monte Carlo method. We calculate the equation of state…

Quantum Gases · Physics 2015-03-17 G. Bertaina , S. Giorgini

We have observed condensation of fermionic atom pairs in the BCS-BEC crossover regime. A trapped gas of fermionic 40K atoms is evaporatively cooled to quantum degeneracy and then a magnetic-field Feshbach resonance is used to control the…

Statistical Mechanics · Physics 2009-11-10 C. A. Regal , M. Greiner , D. S. Jin

We present a systematic theoretical study of the BCS-BEC crossover problem in three-dimensional atomic Fermi gases at zero temperature with a spherical spin-orbit coupling which can be generated by a synthetic non-Abelian gauge field…

Quantum Gases · Physics 2012-07-13 Lianyi He , Xu-Guang Huang

We propose a method for simulating the behaviour of small clusters of particles that explicitly accounts for all mean-field and binary-correlation effects. Our approach leads to a set of variational equations that can be used to study both…

Other Condensed Matter · Physics 2009-11-11 J. N. Milstein , K. Burnett

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

We present a theory of a two-component atomic Fermi gas with tunable attractive contact interactions on a spherical shell going through the Bardeen-Cooper-Schrieffer (BCS) - Bose Einstein condensation (BEC) crossover, inspired by the…

Quantum Gases · Physics 2022-04-01 Yan He , Hao Guo , Chih-Chun Chien

We experimentally investigate the first-order correlation function of a trapped Fermi gas in the two-dimensional BEC-BCS crossover. We observe a transition to a low-temperature superfluid phase with algebraically decaying correlations. We…

Quantum Gases · Physics 2015-07-03 P. A. Murthy , I. Boettcher , L. Bayha , M. Holzmann , D. Kedar , M. Neidig , M. G. Ries , A. N. Wenz , G. Zürn , S. Jochim

We theoretically investigate optical (frequency-dependent) bulk spin transport properties in a spin-1/2 topological Fermi superfluid. We specifically consider a one-dimensional system with an interspin {\it p}-wave interaction, which can be…

Quantum Gases · Physics 2024-01-17 Hiroyuki Tajima , Yuta Sekino , Shun Uchino

We present a theory of two-component atomic Fermi superfluid with tunable pairing interaction in a thin spherical shell subject to spin-orbit coupling (SOC). By incorporating SOC into the Fermi superfluid in the BCS-Bose Einstein…

Quantum Gases · Physics 2025-05-15 Yan He , Chih-Chun Chien

We observe dramatic changes in the atomic momentum distribution of a Fermi gas in the region of the BCS-BEC crossover. We study the shape of the momentum distribution and the kinetic energy as a function of interaction strength. The…

Other Condensed Matter · Physics 2009-11-11 C. A. Regal , M. Greiner , S. Giorgini , M. Holland , D. S. Jin

We discuss the BCS-BEC crossover in a degenerate Fermi gas of two hyperfine states interacting close to a Feshbach resonance. This system has quasi-molecular Bosons associated with a Feshbach resonance, and this kinds of coupled…

Soft Condensed Matter · Physics 2016-08-31 Y. Ohashi , A. Griffin