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Related papers: Shell-Model Monte Carlo Simulations of BCS-BEC Cro…

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We study a trapped system of fermions with an attractive zero-range two-body interaction using the Shell-Model Monte Carlo method. The method provides {\em ab initio} results in the low $N$ limit where mean-field theory is not applicable.…

Superconductivity · Physics 2008-08-04 N. T. Zinner , K. Mølmer , C. Özen , K. Langanke , D. J. Dean

We determine the energetically lowest lying states in the BEC-BCS crossover regime of s-wave interacting two-component Fermi gases under harmonic confinement by solving the many-body Schrodinger equation using two distinct approaches.…

Other Condensed Matter · Physics 2009-11-13 J. von Stecher , C. H. Greene , D. Blume

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

The Quantum Monte Carlo method for spin 1/2 fermions at finite temperature is formulated for dilute systems with an s-wave interaction. The motivation and the formalism are discussed along with descriptions of the algorithm and various…

Statistical Mechanics · Physics 2009-02-05 Aurel Bulgac , Joaquin E. Drut , Piotr Magierski

We investigate the BCS-BEC crossover in a bilayer system of fermionic dipoles at zero temperature using the fixed-node diffusion Monte Carlo technique. The dipoles are confined on two parallel planes separated by a distance $\lambda$ and…

Quantum Gases · Physics 2014-11-26 Natalia Matveeva , Stefano Giorgini

We review quantum Monte Carlo methods for dealing with large shell model problems. These methods reduce the imaginary-time many-body evolution operator to a coherent superposition of one-body evolutions in fluctuating one-body fields; the…

Nuclear Theory · Physics 2009-10-30 S. E. Koonin , D. J. Dean , K. Langanke

We propose a simple bose-fermi model in two dimensions, with a coupling that converts pairs of opposite spin fermions into localized bosons and vice versa. We show that tracing out one of the degrees, either the bosons or fermions,…

Superconductivity · Physics 2020-10-23 Maciej M. Maśka , Nandini Trivedi

We perform a variational quantum Monte Carlo simulation of an interacting Fermi gas confined in a three dimensional harmonic potential. This gas is considered as the precursor system from which a molecular bosonic gas is formed. Based on…

Other Condensed Matter · Physics 2009-11-11 R. Jauregui , R. Paredes , G. Toledo Sanchez

We review results obtained using Shell Model Monte Carlo (SMMC) techniques. These methods reduce the imaginary-time many-body evolution operator to a coherent superposition of one-body evolutions in fluctuating one-body fields; the…

Nuclear Theory · Physics 2009-10-30 S. E. Koonin , D. J. Dean , K. Langanke

The physics of a two-component cold fermi gas is now frequently addressed in laboratories. Usually this is done for large samples of tens to hundreds of thousands of particles. However, it is now possible to produce few-body systems (1-100…

Nuclear Theory · Physics 2014-08-15 C. Özen , N. T. Zinner

We present novel Monte Carlo methods for treating the interacting shell model that allow exact calculations much larger than those heretofore possible. The two-body interaction is linearized by an auxiliary field; Monte Carlo evaluation of…

Nuclear Theory · Physics 2008-11-26 C. W. Johnson , S. E. Koonin , G. H. Lang , W. E. Ormand

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

Quantum Monte Carlo methods find fruitful application in large shell model problems. These methods reduce the imaginary-time many-body evolution operator to a coherent superposition of one-body evolutions in a fluctuating one-body field;…

Nuclear Theory · Physics 2008-02-03 S. E. Koonin

We determine the effects on the BCS-BEC crossover of the energy dependence of the effective two-body interaction, which at low energies is determined by the effective range. To describe interactions with an effective range of either sign,…

Superconductivity · Physics 2008-11-26 L. M. Jensen , H. M. Nilsen , Gentaro Watanabe

The primary work presented in this paper focuses on the calculation of density-density dynamical correlations in an attractive two dimensional Fermi gas in several physically interesting regimes, including the strongly correlated BEC-BCS…

Quantum Gases · Physics 2019-08-27 Ettore Vitali , Jimmy Gonzalez Nunez

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 study the crossover of a quasi-two-dimensional Fermi gas trapped in the radial plane from the Bardeen-Cooper-Schrieffer (BCS) regime to the Bose-Einstein condensation (BEC) regime by crossing a wide Feshbach resonance. We consider two…

Strongly Correlated Electrons · Physics 2008-08-06 Wei Zhang , G. -D. Lin , L. -M. Duan

Using exact continuous quantum Monte Carlo techniques, we study the zero and finite temperature properties of a system of harmonically trapped one dimensional spin 1/2 fermions with short range interactions. Motivated by experimental…

Other Condensed Matter · Physics 2009-11-13 Michele Casula , D. M. Ceperley , Erich J. Mueller

The strongly-correlated regime of the BCS-BEC crossover can be realized by diluting a system of two-component fermions with a short-range attractive interaction. We investigate this system via a novel continuous-space-time diagrammatic…

Strongly Correlated Electrons · Physics 2009-11-13 Evgeni Burovski , Evgeny Kozik , Nikolay Prokof'ev , Boris Svistunov , Matthias Troyer

We discuss finite temperature quantum Monte Carlo methods in the framework of the interacting nuclear shell model. The methods are based on a representation of the imaginary-time many-body propagator as a superposition of one-body…

Nuclear Theory · Physics 2009-11-06 Y. Alhassid
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