Zero-Temperature Properties of a Strongly Interacting Superfluid Fermi Gas in the BCS–BEC Crossover Region

H. Tajima; P. van Wyk; R. Hanai; D. Kagamihara; D. Inotani; M. Horikoshi; Y. Ohashi

doi:10.1007/s10909-016-1691-9

Zero-Temperature Properties of a Strongly Interacting Superfluid Fermi Gas in the BCS–BEC Crossover Region

H. Tajima, P. van Wyk, R. Hanai, D. Kagamihara, D. Inotani, M. Horikoshi, Y. Ohashi

Research output: Contribution to journal › Article › peer-review

3 Citations (Scopus)

Abstract

We investigate thermodynamic properties and effects of quantum fluctuations in the Bardeen–Cooper–Schrieffer (BCS)–Bose–Einstein condensation (BEC) crossover region of a superfluid Fermi gas in the low-temperature limit. Including strong-coupling corrections within the framework of an extended T-matrix approximation, we numerically compute the isothermal compressibility χ_n. While quantum fluctuation effects on χ_n in the strong-coupling BEC regime are explained by the quantum depletion due to a repulsive interaction between tightly bound molecules, effects of self-energy shift on the Fermi chemical potential are found to enhance χ_n in the weak-coupling BCS region. We also show that the calculated χ_n agrees well with the recent experiment on a ⁶Li Fermi gas done from the weak-coupling region to the unitarity limit. Our result would be useful for the study of many-body quantum corrections in the BCS–BEC crossover region of a strongly interacting Fermi superfluid.

Original language	English
Pages (from-to)	677-684
Number of pages	8
Journal	Journal of Low Temperature Physics
Volume	187
Issue number	5-6
DOIs	https://doi.org/10.1007/s10909-016-1691-9
Publication status	Published - 2017 Jun 1

Keywords

BCS–BEC crossover
Quantum fluctuations
Ultracold Fermi gas

ASJC Scopus subject areas

Atomic and Molecular Physics, and Optics
Materials Science(all)
Condensed Matter Physics

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10.1007/s10909-016-1691-9

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title = "Zero-Temperature Properties of a Strongly Interacting Superfluid Fermi Gas in the BCS–BEC Crossover Region",

abstract = "We investigate thermodynamic properties and effects of quantum fluctuations in the Bardeen–Cooper–Schrieffer (BCS)–Bose–Einstein condensation (BEC) crossover region of a superfluid Fermi gas in the low-temperature limit. Including strong-coupling corrections within the framework of an extended T-matrix approximation, we numerically compute the isothermal compressibility χn. While quantum fluctuation effects on χn in the strong-coupling BEC regime are explained by the quantum depletion due to a repulsive interaction between tightly bound molecules, effects of self-energy shift on the Fermi chemical potential are found to enhance χn in the weak-coupling BCS region. We also show that the calculated χn agrees well with the recent experiment on a 6Li Fermi gas done from the weak-coupling region to the unitarity limit. Our result would be useful for the study of many-body quantum corrections in the BCS–BEC crossover region of a strongly interacting Fermi superfluid.",

keywords = "BCS–BEC crossover, Quantum fluctuations, Ultracold Fermi gas",

author = "H. Tajima and {van Wyk}, P. and R. Hanai and D. Kagamihara and D. Inotani and M. Horikoshi and Y. Ohashi",

note = "Funding Information: We thanks to M. Matsumoto for useful discussions. This work was supported by KiPAS project in Keio University. H.T. and R.H. were supported by a grant-in-aid for JSPS fellows. D.I. was supported by grant-in-aid for Young Scientists (B) from JSPS in Japan (No.16K17773). M.H. was supported by grant-in-aid for Scientific Research on Innovative Areas (No. 24105006) and grant-in-aid for Young Scientists (A) from JSPS in Japan (No. 23684033). Y.O. was supported by grant-in-aid for Scientific Research from MEXT and JSPS in Japan (No.15H00840,No.15K00178,No.16K05503). Publisher Copyright: {\textcopyright} 2016, Springer Science+Business Media New York.",

year = "2017",

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doi = "10.1007/s10909-016-1691-9",

language = "English",

volume = "187",

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journal = "Journal of Low Temperature Physics",

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T1 - Zero-Temperature Properties of a Strongly Interacting Superfluid Fermi Gas in the BCS–BEC Crossover Region

AU - Tajima, H.

AU - van Wyk, P.

AU - Hanai, R.

AU - Kagamihara, D.

AU - Inotani, D.

AU - Horikoshi, M.

AU - Ohashi, Y.

N1 - Funding Information: We thanks to M. Matsumoto for useful discussions. This work was supported by KiPAS project in Keio University. H.T. and R.H. were supported by a grant-in-aid for JSPS fellows. D.I. was supported by grant-in-aid for Young Scientists (B) from JSPS in Japan (No.16K17773). M.H. was supported by grant-in-aid for Scientific Research on Innovative Areas (No. 24105006) and grant-in-aid for Young Scientists (A) from JSPS in Japan (No. 23684033). Y.O. was supported by grant-in-aid for Scientific Research from MEXT and JSPS in Japan (No.15H00840,No.15K00178,No.16K05503). Publisher Copyright: © 2016, Springer Science+Business Media New York.

PY - 2017/6/1

Y1 - 2017/6/1

N2 - We investigate thermodynamic properties and effects of quantum fluctuations in the Bardeen–Cooper–Schrieffer (BCS)–Bose–Einstein condensation (BEC) crossover region of a superfluid Fermi gas in the low-temperature limit. Including strong-coupling corrections within the framework of an extended T-matrix approximation, we numerically compute the isothermal compressibility χn. While quantum fluctuation effects on χn in the strong-coupling BEC regime are explained by the quantum depletion due to a repulsive interaction between tightly bound molecules, effects of self-energy shift on the Fermi chemical potential are found to enhance χn in the weak-coupling BCS region. We also show that the calculated χn agrees well with the recent experiment on a 6Li Fermi gas done from the weak-coupling region to the unitarity limit. Our result would be useful for the study of many-body quantum corrections in the BCS–BEC crossover region of a strongly interacting Fermi superfluid.

AB - We investigate thermodynamic properties and effects of quantum fluctuations in the Bardeen–Cooper–Schrieffer (BCS)–Bose–Einstein condensation (BEC) crossover region of a superfluid Fermi gas in the low-temperature limit. Including strong-coupling corrections within the framework of an extended T-matrix approximation, we numerically compute the isothermal compressibility χn. While quantum fluctuation effects on χn in the strong-coupling BEC regime are explained by the quantum depletion due to a repulsive interaction between tightly bound molecules, effects of self-energy shift on the Fermi chemical potential are found to enhance χn in the weak-coupling BCS region. We also show that the calculated χn agrees well with the recent experiment on a 6Li Fermi gas done from the weak-coupling region to the unitarity limit. Our result would be useful for the study of many-body quantum corrections in the BCS–BEC crossover region of a strongly interacting Fermi superfluid.

KW - BCS–BEC crossover

KW - Quantum fluctuations

KW - Ultracold Fermi gas

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SN - 0022-2291

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JO - Journal of Low Temperature Physics

JF - Journal of Low Temperature Physics

IS - 5-6

ER -

Zero-Temperature Properties of a Strongly Interacting Superfluid Fermi Gas in the BCS–BEC Crossover Region

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Keywords

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