Journal of Low Temperature Physics

, Volume 196, Issue 1–2, pp 126–132 | Cite as

Single-Particle Structures in the Normal State of a Strongly Interacting Bose–Fermi Mixture with Mass Imbalance

  • K. ManabeEmail author
  • D. Kagamihara
  • D. Inotani
  • Y. Ohashi


We extend some of the authors’ previous work for a mass-balanced Bose–Fermi mixture to include effects of realistic mass imbalance in a \(^{23}\)Na–\(^{40}\)K and a \(^{87}\)Rb–\(^{40}\)K mixtures. Including effects of pairing fluctuations within the framework of an improved T-matrix theory, we calculate the single-particle spectral weight (SW), as well as the photoemission spectrum (PES) in the unitary regime at the Bose–Einstein condensation temperature \(T_{\mathrm {BEC}}\). We show that the characteristic three-peak structure induced by paring fluctuations, being predicted in the mass-balanced case, remains to exist in SW even in the presence of mass difference. We also show that PES is a useful experimental method to observe this phenomenon in a \(^{23}\)Na–\(^{40}\)K, as well as \(^{87}\)Rb–\(^{40}\)K, Bose–Fermi mixtures. Since this strong-coupling phenomenon is qualitatively different from that in a two-component Fermi gas, our results would be useful in clarifying how the quantum statistics affects Bose and Fermi pairing phenomena in a two-component gas mixture.


Cold atom physics Bose–Fermi mixture Bose–Einstein condensation Strong-coupling effects 



We would like to thank R. Sato for discussions. 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. JP16K05503, JP18K11345, JP18H05406).


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

Authors and Affiliations

  • K. Manabe
    • 1
    Email author
  • D. Kagamihara
    • 1
  • D. Inotani
    • 1
  • Y. Ohashi
    • 1
  1. 1.Department of Physics, Faculty of Science and TechnologyKeio UniversityYokohamaJapan

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