Strong-Coupling Effects on Specific Heat in the BCS–BEC Crossover

Abstract

We theoretically investigate strong-coupling effects on specific heat at constant volume \(C_{\mathrm{V}}\) in a superfluid Fermi gas with a tunable interaction associated with Feshbach resonance. Including fluctuations of the superfluid order parameter within the strong-coupling theory developed by Nozières and Schmitt-Rink, we calculate the temperature dependence of \(C_{\mathrm{V}}\) at the unitarity limit in the superfluid phase. We show that, in the low-temperature region, \(T^3\)-behavior is shown in the temperature dependence of \(C_{\mathrm{V}}\). This result indicates that the low-lying excitations are dominated by the gapless Goldstone mode, associated with the phase fluctuations of the superfluid order parameter. Since the Goldstone mode is one of the most fundamental phenomena in the Fermionic superfluidity, our results are useful for further understanding how the pairing fluctuations affect physical properties in the BCS–BEC crossover physics below the superfluid transition temperature.

This is a preview of subscription content, access via your institution.

Fig. 1
Fig. 2
Fig. 3
Fig. 4

References

  1. 1.

    C.A. Regal, M. Greiner, D.S. Jin, Phys. Rev. Lett. 92, 040403 (2004)

    ADS  Article  Google Scholar 

  2. 2.

    M.W. Zwierlein, C.A. Stan, C.H. Schunck, S.M.F. Raupach, A.J. Kerman, W. Ketterle, Phys. Rev. Lett 92, 120403 (2004)

    ADS  Article  Google Scholar 

  3. 3.

    J. Kinast, S.L. Hemmer, M.E. Gehm, A. Turlapov, J.E. Thomas, Phys. Rev. Lett. 92, 150402 (2004)

    ADS  Article  Google Scholar 

  4. 4.

    M. Bartenstein, A. Altmeyer, S. Riedl, S. Jochim, C. Chin, J.H. Denschlag, R. Grimm, Phys. Rev. Lett 92, 203201 (2004)

    ADS  Article  Google Scholar 

  5. 5.

    S. Tsuchiya, R. Watanabe, Y. Ohashi, Phys. Rev. A 80, 033613 (2009)

    ADS  Article  Google Scholar 

  6. 6.

    S. Tsuchiya, R. Watanabe, Y. Ohashi, Phys. Rev. A 84, 043647 (2011)

    ADS  Article  Google Scholar 

  7. 7.

    H. Tajima, T. Kashimura, R. Hanai, R. Watanabe, Y. Ohashi, Phys. Rev. A 89, 033617 (2014)

    ADS  Article  Google Scholar 

  8. 8.

    R. Haussmann, W. Rantner, S. Cerrito, W. Zwerger, Phys. Rev. A 75, 023610 (2007)

    ADS  Article  Google Scholar 

  9. 9.

    H. Hu, X.-J. Liu, P.D. Drummond, Phys. Rev. A 73, 023617 (2006)

    ADS  Article  Google Scholar 

  10. 10.

    P. van Wyk, H. Tajima, R. Hanai, Y. Ohashi, Phys. Rev. A 93, 013621 (2016)

    ADS  Article  Google Scholar 

  11. 11.

    J. Kinast, A. Turpalov, J.E. Thomas, Q. Chen, J. Stajic, K. Levin, Science 307, 1296 (2005)

    ADS  Article  Google Scholar 

  12. 12.

    L. Luo, J.E. Thomas, J. Low. Temp. Phys 154, 1 (2009)

    ADS  Article  Google Scholar 

  13. 13.

    M. Horikoshi, S. Nakajima, M. Ueda, T. Mukaiyama, Science 327, 442 (2010)

    ADS  Article  Google Scholar 

  14. 14.

    S. Nascimbene, N. Navon, K.J. Jiang, F. Chevy, C. Salomon, Nature 463, 1057 (2010)

    ADS  Article  Google Scholar 

  15. 15.

    M.J.H. Ku, A.T. Sommer, L.W. Cheuk, M.W. Zwierlein, Science. 335, 563–567 (2012)

    ADS  Article  Google Scholar 

  16. 16.

    Y. Ohashi, A. Griffin, Phys. Rev. A 67, 063612 (2003)

    ADS  Article  Google Scholar 

  17. 17.

    P. Nozières, S. Schmitt-Rink, J. Low Temp. Phys. 59, 195 (1985)

    ADS  Article  Google Scholar 

  18. 18.

    N. Fukushima, Y. Ohashi, E. Taylor, A. Griffin, Phys. Rev. A 75, 033609 (2007)

    ADS  Article  Google Scholar 

  19. 19.

    H. Hu, X.-J. Liu, P.D. Drummond, Europhys. Lett. 74, 574 (2006)

    ADS  Article  Google Scholar 

  20. 20.

    R. Watanabe, S. Tsuchiya, Y. Ohashi, Phys. Rev. A 82, 043630 (2010)

    ADS  Article  Google Scholar 

  21. 21.

    R. Haussmann, W. Rantner, S. Cerrito, W. Zwerger, Phys. Rev. A 75, 023610 (2007)

    ADS  Article  Google Scholar 

Download references

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 (Nos. JP18K11345, JP18H05406, JP16K05503).

Author information

Affiliations

Authors

Corresponding author

Correspondence to Daisuke Inotani.

Additional information

Publisher's Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Inotani, D., van Wyk, P. & Ohashi, Y. Strong-Coupling Effects on Specific Heat in the BCS–BEC Crossover. J Low Temp Phys 196, 111–118 (2019). https://doi.org/10.1007/s10909-019-02194-7

Download citation

Keywords

  • Specific heat
  • BCS–BEC crossover
  • Ultracold Fermi gas
  • Goldstone mode