Superfluid-ferromagnet-superfluid junction and the π phase in a superfluid Fermi gas

Takashi Kashimura, Shunji Tsuchiya, Yoji Ohashi

Research output: Contribution to journalArticle

4 Citations (Scopus)

Abstract

We investigate the possibility of a superfluid-ferromagnet-superfluid (SFS) junction in a superfluid Fermi gas. To examine this possibility in a simple manner, we consider an attractive Hubbard model at T=0 within the mean-field theory. When a potential barrier is embedded in a superfluid Fermi gas with population imbalance (N↑>N↓, where Nσ is the number of atoms with pseudospin σ= ↑, ↓), this barrier is shown to be magnetized in the sense that excess ↑-spin atoms are localized around it. The resulting superfluid Fermi gas is spatially divided into two by this ferromagnet, so that one obtains a junction similar to the superconductor- ferromagnet-superconductor junction discussed in superconductivity. Indeed, we show that the so-called π phase, which is a typical phenomenon in the SFS junction, is realized, where the superfluid order parameter changes its sign across the junction. Our results would be useful for the study of magnetic effects on fermion superfluidity using an ultracold Fermi gas.

Original languageEnglish
Article number033617
JournalPhysical Review A - Atomic, Molecular, and Optical Physics
Volume82
Issue number3
DOIs
Publication statusPublished - 2010 Sep 24

Fingerprint

gases
magnetic effects
superfluidity
atoms
superconductivity
fermions

ASJC Scopus subject areas

  • Atomic and Molecular Physics, and Optics

Cite this

Superfluid-ferromagnet-superfluid junction and the π phase in a superfluid Fermi gas. / Kashimura, Takashi; Tsuchiya, Shunji; Ohashi, Yoji.

In: Physical Review A - Atomic, Molecular, and Optical Physics, Vol. 82, No. 3, 033617, 24.09.2010.

Research output: Contribution to journalArticle

@article{e1aeb4baa15146c485fb81d46721bb66,
title = "Superfluid-ferromagnet-superfluid junction and the π phase in a superfluid Fermi gas",
abstract = "We investigate the possibility of a superfluid-ferromagnet-superfluid (SFS) junction in a superfluid Fermi gas. To examine this possibility in a simple manner, we consider an attractive Hubbard model at T=0 within the mean-field theory. When a potential barrier is embedded in a superfluid Fermi gas with population imbalance (N↑>N↓, where Nσ is the number of atoms with pseudospin σ= ↑, ↓), this barrier is shown to be magnetized in the sense that excess ↑-spin atoms are localized around it. The resulting superfluid Fermi gas is spatially divided into two by this ferromagnet, so that one obtains a junction similar to the superconductor- ferromagnet-superconductor junction discussed in superconductivity. Indeed, we show that the so-called π phase, which is a typical phenomenon in the SFS junction, is realized, where the superfluid order parameter changes its sign across the junction. Our results would be useful for the study of magnetic effects on fermion superfluidity using an ultracold Fermi gas.",
author = "Takashi Kashimura and Shunji Tsuchiya and Yoji Ohashi",
year = "2010",
month = "9",
day = "24",
doi = "10.1103/PhysRevA.82.033617",
language = "English",
volume = "82",
journal = "Physical Review A",
issn = "2469-9926",
publisher = "American Physical Society",
number = "3",

}

TY - JOUR

T1 - Superfluid-ferromagnet-superfluid junction and the π phase in a superfluid Fermi gas

AU - Kashimura, Takashi

AU - Tsuchiya, Shunji

AU - Ohashi, Yoji

PY - 2010/9/24

Y1 - 2010/9/24

N2 - We investigate the possibility of a superfluid-ferromagnet-superfluid (SFS) junction in a superfluid Fermi gas. To examine this possibility in a simple manner, we consider an attractive Hubbard model at T=0 within the mean-field theory. When a potential barrier is embedded in a superfluid Fermi gas with population imbalance (N↑>N↓, where Nσ is the number of atoms with pseudospin σ= ↑, ↓), this barrier is shown to be magnetized in the sense that excess ↑-spin atoms are localized around it. The resulting superfluid Fermi gas is spatially divided into two by this ferromagnet, so that one obtains a junction similar to the superconductor- ferromagnet-superconductor junction discussed in superconductivity. Indeed, we show that the so-called π phase, which is a typical phenomenon in the SFS junction, is realized, where the superfluid order parameter changes its sign across the junction. Our results would be useful for the study of magnetic effects on fermion superfluidity using an ultracold Fermi gas.

AB - We investigate the possibility of a superfluid-ferromagnet-superfluid (SFS) junction in a superfluid Fermi gas. To examine this possibility in a simple manner, we consider an attractive Hubbard model at T=0 within the mean-field theory. When a potential barrier is embedded in a superfluid Fermi gas with population imbalance (N↑>N↓, where Nσ is the number of atoms with pseudospin σ= ↑, ↓), this barrier is shown to be magnetized in the sense that excess ↑-spin atoms are localized around it. The resulting superfluid Fermi gas is spatially divided into two by this ferromagnet, so that one obtains a junction similar to the superconductor- ferromagnet-superconductor junction discussed in superconductivity. Indeed, we show that the so-called π phase, which is a typical phenomenon in the SFS junction, is realized, where the superfluid order parameter changes its sign across the junction. Our results would be useful for the study of magnetic effects on fermion superfluidity using an ultracold Fermi gas.

UR - http://www.scopus.com/inward/record.url?scp=77957124598&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=77957124598&partnerID=8YFLogxK

U2 - 10.1103/PhysRevA.82.033617

DO - 10.1103/PhysRevA.82.033617

M3 - Article

AN - SCOPUS:77957124598

VL - 82

JO - Physical Review A

JF - Physical Review A

SN - 2469-9926

IS - 3

M1 - 033617

ER -