Finitesize and particlenumber effects in an ultracold Fermi gas at unitarity
Abstract
We investigate an ultracold Fermi gas at unitarity confined in a periodic box V=L{sup 3} using renormalization group techniques. Within this approach we can quantitatively assess the longrange bosonic order parameter fluctuations, which dominate finitesize effects. We determine the finitesize and particlenumber dependence of universal quantities, such as the Bertsch parameter and the fermion gap. Moreover, we analyze how these universal observables respond to the variation of an external pairing source. Our results indicate that the Bertsch parameter saturates rather quickly to its value in the thermodynamic limit as a function of increasing box size. On the other hand, we observe that the fermion gap shows a significantly stronger dependence on the box size, in particular for small values of the pairing source. Our results may contribute to a better understanding of finitesize and particlenumber effects present in Monte Carlo simulations of ultracold Fermi gases.
 Authors:

 TheoretischPhysikalisches Institut, FriedrichSchillerUniversitaet Jena, MaxWienPlatz 1, D07743 Jena (Germany)
 Institut fuer Theoretische Physik, Universitaet Innsbruck, A6020 Innsbruck (Austria)
 Institut fuer Theoretische Festkoerperphysik, RWTH Aachen, OttoBlumenthalstrasse, D52074 Aachen (Germany)
 Publication Date:
 OSTI Identifier:
 22095667
 Resource Type:
 Journal Article
 Journal Name:
 Physical Review. A
 Additional Journal Information:
 Journal Volume: 84; Journal Issue: 6; Other Information: (c) 2011 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 10502947
 Country of Publication:
 United States
 Language:
 English
 Subject:
 71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; 74 ATOMIC AND MOLECULAR PHYSICS; COMPUTERIZED SIMULATION; FERMI GAS; FERMIONS; FLUCTUATIONS; INTERACTION RANGE; MONTE CARLO METHOD; ORDER PARAMETERS; PERIODICITY; RENORMALIZATION; UNITARITY
Citation Formats
Braun, Jens, Diehl, Sebastian, Institute for Quantum Optics and Quantum Information of the Austrian Academy of Sciences, A6020 Innsbruck, and Scherer, Michael M. Finitesize and particlenumber effects in an ultracold Fermi gas at unitarity. United States: N. p., 2011.
Web. doi:10.1103/PHYSREVA.84.063616.
Braun, Jens, Diehl, Sebastian, Institute for Quantum Optics and Quantum Information of the Austrian Academy of Sciences, A6020 Innsbruck, & Scherer, Michael M. Finitesize and particlenumber effects in an ultracold Fermi gas at unitarity. United States. https://doi.org/10.1103/PHYSREVA.84.063616
Braun, Jens, Diehl, Sebastian, Institute for Quantum Optics and Quantum Information of the Austrian Academy of Sciences, A6020 Innsbruck, and Scherer, Michael M. Thu .
"Finitesize and particlenumber effects in an ultracold Fermi gas at unitarity". United States. https://doi.org/10.1103/PHYSREVA.84.063616.
@article{osti_22095667,
title = {Finitesize and particlenumber effects in an ultracold Fermi gas at unitarity},
author = {Braun, Jens and Diehl, Sebastian and Institute for Quantum Optics and Quantum Information of the Austrian Academy of Sciences, A6020 Innsbruck and Scherer, Michael M.},
abstractNote = {We investigate an ultracold Fermi gas at unitarity confined in a periodic box V=L{sup 3} using renormalization group techniques. Within this approach we can quantitatively assess the longrange bosonic order parameter fluctuations, which dominate finitesize effects. We determine the finitesize and particlenumber dependence of universal quantities, such as the Bertsch parameter and the fermion gap. Moreover, we analyze how these universal observables respond to the variation of an external pairing source. Our results indicate that the Bertsch parameter saturates rather quickly to its value in the thermodynamic limit as a function of increasing box size. On the other hand, we observe that the fermion gap shows a significantly stronger dependence on the box size, in particular for small values of the pairing source. Our results may contribute to a better understanding of finitesize and particlenumber effects present in Monte Carlo simulations of ultracold Fermi gases.},
doi = {10.1103/PHYSREVA.84.063616},
url = {https://www.osti.gov/biblio/22095667},
journal = {Physical Review. A},
issn = {10502947},
number = 6,
volume = 84,
place = {United States},
year = {2011},
month = {12}
}