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Related papers: Functional Integral for Ultracold Fermionic Atoms

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We present a time-independent quantum formalism to describe the dynamics of molecules with permanent electric dipole moments in a two-dimensional confined geometry such as a one-dimensional optical lattice, in the presence of an electric…

Atomic Physics · Physics 2011-01-17 Goulven Quéméner , John L. Bohn

We consider a two-species degenerate Fermi gas coupled by a diatomic Feshbach resonance. We show that the resulting superfluid can exhibit a form of coherent BEC-to-BCS oscillations in response to a nonadiabatic change in the system's…

Superconductivity · Physics 2007-05-23 A. V. Andreev , V. Gurarie , L. Radzihovsky

Few-body physics related to the Efimov effect is discussed using the functional renormalization group method. After a short review of renormalization in its modern formulation we apply this formalism to the description of scattering and…

Quantum Gases · Physics 2012-08-20 Stefan Floerchinger , Sergej Moroz , Richard Schmidt

We present a method for performing path integral molecular dynamics (PIMD) simulations for fermions and address its sign problem. PIMD simulations are widely used for studying many-body quantum systems at thermal equilibrium. However, they…

Chemical Physics · Physics 2020-05-07 Barak Hirshberg , Michele Invernizzi , Michele Parrinello

By recognizing the vital importance of two-hole Cooper pairs (CPs) in addition to the usual two-electron ones in a strongly-interacting many-electron system, the concept of CPs was re-examined with striking conclusions. Based on this,…

Superconductivity · Physics 2009-11-11 M. de Llano , M. Grether

The second order response functions and susceptibilities of finite temperature Bose-Einstein Condensates (BEC) in a one dimensional harmonic trap driven by an external field that couples to the particle density are calculated by solving the…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 S. Choi , O. Berman , V. Chernyak , S. Mukamel

We develop a self-consistent theory unifying the description of a quantum Fermi gas in the presence of a Fano-Feshbach resonance in the whole phase diagram ranging from BCS to BEC type of superfluidity and from narrow to broad resonances,…

Quantum Gases · Physics 2019-08-29 Pietro Maria Bonetti , Maria Luisa Chiofalo

We investigate the Bose-Einstein condensation (BEC, superfluidity) of particle-hole pairs in ultracold Fermionic atoms with repulsive interactionsand arbitrary polarization, which are trapped within optical lattices. Near a Feshbach…

Atomic Physics · Physics 2007-05-23 Chaohong Lee

We study the crossover from the Bardeen-Cooper-Shrieffer (BCS) regime to the Bose-Einstein-condensation (BEC) regime in a quasi-two-dimensional quantum gas of ultracold fermionic atoms. Using an effective two-dimensional Hamiltonian with…

Quantum Gases · Physics 2023-08-16 Jing Zhou , Tingting Shi , Xia-Ji Liu , Hui Hu , Wei Zhang

Ultracold atom gases provide model systems in which many-body quantum physics phenomena can be studied. Recent experiments on Fermi gases have realized a phase transition to a Fermi superfluid state with strong interparticle interactions.…

Other Condensed Matter · Physics 2008-09-04 J. T. Stewart , J. P. Gaebler , D. S. Jin

We review the BCS to Bose Einstein condensation (BEC) crossover scenario which is based on the well known crossover generalization of the BCS ground state wavefunction $\Psi_0$. While this ground state has been summarized extensively in the…

Superconductivity · Physics 2011-09-13 Qijin Chen , Jelena Stajic , Shina Tan , Kathryn Levin

We investigate the Feshbach conversion of fermion atomic pairs to condensed boson molecules with a microscopic model that accounts the repulsive interactions among all the particles involved. We find that the conversion efficiency is…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 Jie Liu , Li-Bin Fu , Bin Liu , Biao Wu

This article is written as a Lecture given in the 2006 Varenna Summer School on "Ultracold Fermi Gases". Here we present a review of BCS--Bose Einstein condensation (BEC) crossover theory with emphasis on finite temperature effects. We…

Strongly Correlated Electrons · Physics 2011-09-13 K. Levin , Qijin Chen

We derive a set of dynamical mean-field equations for strongly interacting fermionic atoms in a potential trap across a Feshbach resonance. Our derivation is based on a variational ansatz, which generalizes the crossover wavefunction to the…

Other Condensed Matter · Physics 2007-05-23 W. Yi , L. -M. Duan

Atomic and molecular samples reduced to temperatures below 1 microkelvin, yet still in the gas phase, afford unprecedented energy resolution in probing and manipulating how their constituent particles interact with one another. For simple…

We consider the photoassociation of a low-density gas of quantum-degenerate trapped fermionic atoms into bosonic molecules in a spherically symmetric harmonic potential. For a dilute system and the photoassociation coupling energy small…

Mesoscale and Nanoscale Physics · Physics 2009-11-10 Takahiko Miyakawa , Pierre Meystre

We study the ground state phase diagram of a mixture of bosonic and fermionic cold atoms confined on two- and three-dimensional optical lattices. The coupling between bosonic fluctuations and fermionic atoms can be attractive or repulsive…

Quantum Gases · Physics 2010-05-27 T. P. Polak , T. K. Kopeć

We investigate magnetoassociation of ultracold fermionic Feshbach molecules in a mixture of $^{40}$K and $^{87}$Rb atoms, where we can create as many as $7\times 10^4$ $^{40}$K$^{87}$Rb molecules with a conversion efficiency as high as 45%.…

Quantum Gases · Physics 2013-09-12 Tyler D. Cumby , Ruth A. Shewmon , Ming-Guang Hu , John D. Perreault , Deborah S. Jin

We develop a functional integral formulation for binary Bose-Einstein condensates coupled to polarized fermions. We find that spin-dependent fermion-mediated interactions have dramatic effects on the properties of the binary condensates.…

Quantum Gases · Physics 2020-12-03 Renyuan Liao

Classical fields approximation to cold weakly interacting bosons allows for a unified treatment of condensed and uncondensed parts of the system. Until now, however, the quantitative predictions were limited by a dependence of the results…

Other Condensed Matter · Physics 2009-11-10 Lukasz Zawitkowski , Miroslaw Brewczyk , Mariusz Gajda , Kazimierz Rzazewski