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Related papers: Driving superfluidity with photoassociation

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We investigate density fluctuations in a coherent ensemble of interacting fermionic atoms. Adapting the concept of full counting statistics, well-known from quantum optics and mesoscopic electron transport, we study second-order as well as…

Superconductivity · Physics 2022-08-19 W. Belzig , C. Schroll , C. Bruder

We experimentally investigate various processes present in the photoassociative interaction of an ultracold atomic sample with shaped femtosecond laser pulses. We demonstrate the photoassociation of pairs of rubidium atoms into…

A debated issue in the physics of the BCS-BEC crossover with trapped Fermi atoms is to identify characteristic properties of the superfluid phase. Recently, a condensate fraction was measured on the BCS side of the crossover by sweeping the…

Superconductivity · Physics 2007-05-23 A. Perali , P. Pieri , G. C. Strinati

We study two-body correlations in a spin-balanced ultracold harmonically trapped Fermi gas of $^6$Li atoms in the crossover from the Bardeen-Cooper-Schrieffer (BCS) to the Bose-Einstein-Condensate (BEC) regime. For this, we precisely…

Quantum Gases · Physics 2023-10-02 Manuel Jäger , Johannes Hecker Denschlag

We use the density functional method to examine the properties of the nonuniform (two-phase) fluid of two-level atoms, a part of which is excited. Basing on the analysis of the equation of state of a gas of two-level atoms, a part of which…

Soft Condensed Matter · Physics 2007-05-23 Oleg Derzhko , Vasyl Myhal

Ultracold atomic gases are a powerful tool to experimentally study strongly correlated quantum many-body systems. In particular, ultracold Fermi gases with tunable interactions have allowed to realize the famous BEC-BCS crossover from a…

At finite temperature, the hydrodynamic collective modes of superfluid trapped Fermi gases are coupled to the motion of the normal component, which in the BCS limit behaves like a collisionless normal Fermi gas. The coupling between the…

Other Condensed Matter · Physics 2008-11-26 M. Urban

We briefly discuss recent experiments on the BCS-BEC crossover with ultracold alkali-metal atoms both in three-dimensional configurations and two-dimensional ones. Then we analyze the quantum-field-theory formalism used to describe an…

Quantum Gases · Physics 2016-02-26 L. Salasnich

Physical properties of an ultracold Fermi gas in the temperature-coupling phase diagram can be characterized by the contact intensity C, which enters the pair-correlation function at short distances and describes how the two-body problem…

Quantum Gases · Physics 2010-09-02 F. Palestini , A. Perali , P. Pieri , G. C. Strinati

Atomic ensembles strongly interacting with light constitute rich quantum-optical many-body systems, with the potential for observing cooperative effects and dissipative nonequilibrium phase transitions. We theoretically analyze the…

Quantum Physics · Physics 2025-01-28 Janne Ruostekoski

The crossover from weak coupling Bardeen-Cooper-Schrieffer (BCS) pairing to a Bose-Einstein condensate (BEC) of tightly bound pairs, as a function of the attractive interaction in Fermi systems, has long been of interest to theoretical…

Quantum Gases · Physics 2014-04-09 Mohit Randeria , Edward Taylor

This review is written at the time of the twentieth anniversary of the discovery of high temperature superconductors, which, nearly coincides with the important discovery of the superfluid phases of ultracold trapped fermionic atoms. We…

Superconductivity · Physics 2011-09-13 Qijin Chen , Jelena Stajic , K. Levin

We study the detection of a BCS transition within a sample of Lithium--6 atoms confined in a harmonic trap. Using the local density approximation we calculate the pair correlation function in the normal and superfluid state at zero…

Superconductivity · Physics 2009-10-31 F. Weig , W. Zwerger

The superfluid properties of a two-state Fermi mixture in an optical lattice are profoundly modified when an imbalance in the population of the two states is present.We present analytical solutions for the free energy, and for the gap and…

Superconductivity · Physics 2007-08-30 J. Tempere , M. Wouters , J. T. Devreese

We study the dynamics of counterflowing bosonic and fermionic lithium atoms. First, by tuning the interaction strength we measure the critical velocity vc of the system in the BEC-BCS crossover in the low temperature regime and we compare…

Recent advances in experimental techniques allow one to create a quantum point contact between two Fermi superfluids in cold atomic gases with a tunable transmission coefficient. In this Letter we propose that three distinct behaviors of…

Quantum Gases · Physics 2018-10-17 Juan Yao , Boyang Liu , Mingyuan Sun , Hui Zhai

Two-photon photoassociation of hot magnesium atoms by femtosecond laser pulses, creating electronically excited magnesium dimer molecules, is studied from first principles, combining \textit{ab initio} quantum chemistry and molecular…

We compare strategies for evaporative and sympathetic cooling of two-species Fermi-Bose mixtures in single-color and two-color optical dipole traps. We show that in the latter case a large heat capacity of the bosonic species can be…

Condensed Matter · Physics 2009-11-10 Carlo Presilla , Roberto Onofrio

The problem of photonic phase transition for the system of a two-level atomic ensemble interacting with a quantized single-mode electromagnetic field in the presence of optical collisions (OC) is considered. We have shown that for large and…

Mesoscale and Nanoscale Physics · Physics 2015-05-27 A. P. Alodjants , I. Yu. Chestnov , S. M. Arakelian

An integrating theoretical scenario of superconductivity and superfluidity has been built. It reduces to the special BCS superconductivity mechanism for conventional superconductor and to a new theory for high transition temperature…

Superconductivity · Physics 2007-05-23 Jie Han