Advertisement

Isothermal Compressibility of an Ultracold Fermi Gas in the BCS–BEC Crossover

  • R. Sato
  • D. Kagamihara
  • K. Manabe
  • D. Inotani
  • Y. Ohashi
Article
  • 18 Downloads

Abstract

We theoretically investigate the isothermal compressibility \(\kappa _{\mathrm{T}}\) in the normal state of an ultracold Fermi gas with a tunable attractive interaction. We calculate this thermodynamic quantity by considering fluctuations in the Cooper channel, within the framework of the self-consistent T-matrix approximation (SCTMA). For comparison, we also evaluate this quantity in a “non”-self-consistent T-matrix approximation (TMA). We show that the calculated \(\kappa _{\mathrm{T}}\) diverges at \(T_{\mathrm{c}}\) in the BCS–BEC crossover region. On the other hand, such a singular behavior is absent when we deal with this quantity in SCTMA. We point out that the origin of this difference is the neglect of an effective inter-pair interaction in the former approximation. We also explicitly show how such an interaction is involved in the theory when one deals with pairing fluctuations in SCTMA. Our results indicate that the isothermal compressibility is a useful quantity in considering how preformed Cooper pairs interact with one another in the BCS–BEC crossover regime of an ultracold Fermi gas.

Keywords

Isothermal compressibility Ultracold Fermi gas Repulsive inter-pair interaction 

Notes

Acknowledgements

This work was supported by KiPAS project in Keio University. DI was supported by Grant-in-aid for Scientific Research from JSPS in Japan (No. JP16K17773). YO was supported by Grant-in-aid for Scientific Research from MEXT and JSPS in Japan (No. JP16K05503).

References

  1. 1.
    S. Giorgini, L. Pitaevskii, S. Stringari, Rev. Mod. Phys. 80, 1215 (2008)ADSCrossRefGoogle Scholar
  2. 2.
    I. Bloch, J. Dalobard, W. Zwerger, Rev. Mod. Phys. 80, 885 (2008)ADSCrossRefGoogle Scholar
  3. 3.
    C. Chin, R. Grimm, P. Julienne, E. Tiesinga, Rev. Mod. Phys. 80, 1215 (2008)CrossRefGoogle Scholar
  4. 4.
    P. Nozières, S. Schmitt-Rink, J. Low Temp. Phys. 59, 195 (1985)ADSCrossRefGoogle Scholar
  5. 5.
    C.A.R. Sá de Melo, M. Randeria, J.R. Engelbrecht, Phys. Rev. Lett. 71, 3202 (1993)ADSCrossRefGoogle Scholar
  6. 6.
    Y. Ohashi, A. Griffin, Phys. Rev. Lett. 89, 130402 (2002)ADSCrossRefGoogle Scholar
  7. 7.
    C.A. Regal, M. Greiner, D.S. Jin, Phys. Rev. Lett. 92, 040403 (2004)ADSCrossRefGoogle Scholar
  8. 8.
    M.W. Zwierlein, C.A. Stan, C.H. Shunck, S.M.F. Raupach, A.J. Kerman, W. Ketterle, Phys. Rev. Lett. 92, 120403 (2004)ADSCrossRefGoogle Scholar
  9. 9.
    M.J.H. Ku, A.T. Sommer, L.W. Cheuk, M.W. Zwierlein, Science 335, 563 (2012)ADSCrossRefGoogle Scholar
  10. 10.
    A. Sommer, M. Ku, G. Roati, M.W. Zwierlein, Nature 472, 201 (2011)ADSCrossRefGoogle Scholar
  11. 11.
    L. Luo, B. Clancy, J. Joseph, J. Kinast, J.E. Thomas, Phys. Rev. Lett. 98, 080402 (2007)ADSCrossRefGoogle Scholar
  12. 12.
    R. Haussmann, W. Rantner, S. Cerrito, W. Zwerger, Phys. Rev. A 75, 023610 (2007)ADSCrossRefGoogle Scholar
  13. 13.
    F. Palestini, P. Pieri, G.C. Strinati, Phys. Rev. Lett. 108, 080401 (2012)ADSCrossRefGoogle Scholar
  14. 14.
    R. Hausmann, Z. Phys. B 91, 291 (1993)ADSCrossRefGoogle Scholar
  15. 15.
    P. Pieri, G.C. Strinati, Phys. Rev. B 61, 15370 (2000)ADSCrossRefGoogle Scholar
  16. 16.
    R. Haussmann, Phys. Rev. B 49, 12975 (1994)ADSCrossRefGoogle Scholar
  17. 17.
    D.J. Thouless, Ann. Phys. 10, 553 (1960)ADSMathSciNetCrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media, LLC, part of Springer Nature 2018

Authors and Affiliations

  • R. Sato
    • 1
  • D. Kagamihara
    • 1
  • K. Manabe
    • 1
  • D. Inotani
    • 1
  • Y. Ohashi
    • 1
  1. 1.Department of PhysicsKeio UniversityYokohamaJapan

Personalised recommendations