Abstract
We discuss an idea to realize a spontaneous current in a superfluid Fermi gas. When a polarized Fermi superfluid (NN, where Nσ is the number of atoms in the hyperfine state described by pseudospin σ=) is loaded onto a ring-shaped trap with a weak potential barrier, some excess atoms (ΔN=N-N) are localized around the barrier. As shown in our previous paper, this polarized potential barrier works as a π junction in the sense that the superfluid order parameter changes its sign across the barrier. Because of this, the phase of the superfluid order parameter outside the junction is shown to be twisted by π along the ring, which naturally leads to a circulating supercurrent. While the ordinary supercurrent state is obtained as a metastable state, this spontaneous current state is shown to be more stable than the case with no current. Our results indicate that localized excess atoms would be useful for the manipulation of the superfluid order parameter in cold Fermi gases.
| Original language | English |
|---|---|
| Article number | 013609 |
| Journal | Physical Review A - Atomic, Molecular, and Optical Physics |
| Volume | 84 |
| Issue number | 1 |
| DOIs | |
| Publication status | Published - 2011 Jul 20 |
| Externally published | Yes |
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ASJC Scopus subject areas
- Atomic and Molecular Physics, and Optics
Cite this
π junction and spontaneous current state in a superfluid Fermi gas. / Kashimura, Takashi; Tsuchiya, Shunji; Ohashi, Yoji.
In: Physical Review A - Atomic, Molecular, and Optical Physics, Vol. 84, No. 1, 013609, 20.07.2011.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - π junction and spontaneous current state in a superfluid Fermi gas
AU - Kashimura, Takashi
AU - Tsuchiya, Shunji
AU - Ohashi, Yoji
PY - 2011/7/20
Y1 - 2011/7/20
N2 - We discuss an idea to realize a spontaneous current in a superfluid Fermi gas. When a polarized Fermi superfluid (NN, where Nσ is the number of atoms in the hyperfine state described by pseudospin σ=) is loaded onto a ring-shaped trap with a weak potential barrier, some excess atoms (ΔN=N-N) are localized around the barrier. As shown in our previous paper, this polarized potential barrier works as a π junction in the sense that the superfluid order parameter changes its sign across the barrier. Because of this, the phase of the superfluid order parameter outside the junction is shown to be twisted by π along the ring, which naturally leads to a circulating supercurrent. While the ordinary supercurrent state is obtained as a metastable state, this spontaneous current state is shown to be more stable than the case with no current. Our results indicate that localized excess atoms would be useful for the manipulation of the superfluid order parameter in cold Fermi gases.
AB - We discuss an idea to realize a spontaneous current in a superfluid Fermi gas. When a polarized Fermi superfluid (NN, where Nσ is the number of atoms in the hyperfine state described by pseudospin σ=) is loaded onto a ring-shaped trap with a weak potential barrier, some excess atoms (ΔN=N-N) are localized around the barrier. As shown in our previous paper, this polarized potential barrier works as a π junction in the sense that the superfluid order parameter changes its sign across the barrier. Because of this, the phase of the superfluid order parameter outside the junction is shown to be twisted by π along the ring, which naturally leads to a circulating supercurrent. While the ordinary supercurrent state is obtained as a metastable state, this spontaneous current state is shown to be more stable than the case with no current. Our results indicate that localized excess atoms would be useful for the manipulation of the superfluid order parameter in cold Fermi gases.
UR - http://www.scopus.com/inward/record.url?scp=79961105200&partnerID=8YFLogxK
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U2 - 10.1103/PhysRevA.84.013609
DO - 10.1103/PhysRevA.84.013609
M3 - Article
AN - SCOPUS:79961105200
VL - 84
JO - Physical Review A
JF - Physical Review A
SN - 2469-9926
IS - 1
M1 - 013609
ER -