We study the pairing of Fermi gases near the scattering resonance of the l not equal 0 partial wave. Using a model potential which reproduces the actual two-body low energy scattering amplitude, we have obtained an analytic solution of the gap equation. We show that the ground state of l=1 and l=3 superfluids are orbital ferromagnets with pairing wave functions Y11 and Y32, respectively. For l=2, there is a degeneracy between Y22 and a "cyclic state." Dipole energy will orient the angular momentum axis. The gap function can be determined by the angular dependence of the momentum distribution of the fermions.We study the pairing of Fermi gases near the scattering resonance of the l not equal 0 partial wave. Using a model potential which reproduces the actual two-body low energy scattering amplitude, we have obtained an analytic solution of the gap equation. We show that the ground state of l=1 and l=3 superfluids are orbital ferromagnets with pairing wave functions Y11 and Y32, respectively. For l=2, there is a degeneracy between Y22 and a "cyclic state." Dipole energy will orient the angular momentum axis. The gap function can be determined by the angular dependence of the momentum distribution of the fermions.

arXiv:cond-mat/0408468Physical Review LettersMar 9, 2005102 citations

Low-Energy Excitations in a Fermionic Superfluid

Andreas Schmitt

Lecture notes in physicsJun 13, 20140 citations

High Temperature Universal Properties of Atomic Gases Near Feshbach Resonance with Non-Zero Orbital Angular Momentum

Tin-Lun Ho, Neldeltcho Zahariev

We show that the high temperature behavior of atomic gases near Feshbach Resonance with non-zero orbital angular momentum $(\ell >0)$ belong to a universality class different from that of s-wave resonances. The universal interaction energy is $2(2\ell +1)$ times larger than that of the s-wave when approaching the resonance from the atomic side, but is essentially zero on the molecular side; contrary to s-wave resonances where interaction energies on both sides are the same except for a sign change. The measurement of these universality properties should be feasible in current experiments.We show that the high temperature behavior of atomic gases near Feshbach Resonance with non-zero orbital angular momentum $(\ell >0)$ belong to a universality class different from that of s-wave resonances. The universal interaction energy is $2(2\ell +1)$ times larger than that of the s-wave when approaching the resonance from the atomic side, but is essentially zero on the molecular side; contrary to s-wave resonances where interaction energies on both sides are the same except for a sign change. The measurement of these universality properties should be feasible in current experiments.

arXiv:cond-mat/0408469Aug 21, 20040 citations

Angular Momentum of Multiply Quantised Vortices in Fermionic Superfluids

Abhinav Prem, Sergej Moroz, Victor Gurarie +1 more

Bulletin of the American Physical SocietyMar 14, 20170 citations

Orbital Angular Momentum and Spectral Flow in Two-Dimensional Chiral Superfluids

Yasuhiro Tada, Wenxing Nie, Masaki Oshikawa

We study the orbital angular momentum (OAM) ${L}_{z}$ in two-dimensional chiral $({p}_{x}+i{p}_{y}{)}^{\ensuremath{\nu}}$-wave superfluids (SFs) of $N$ fermions on a disk at zero temperature, in terms of spectral asymmetry and spectral flow. It is shown that ${L}_{z}=\ensuremath{\nu}N/2$ for any integer $\ensuremath{\nu}$, in the Bose-Einstein condensation regime. In contrast, in the BCS limit, while the OAM is ${L}_{z}=N/2$ for the $p+ip$ -wave SF, for chiral SFs with $\ensuremath{\nu}\ensuremath{\ge}2$, the OAM is remarkably suppressed as ${L}_{z}=N\ifmmode\times\else\texttimes\fi{}O({\mathrm{\ensuremath{\Delta}}}_{0}/{ϵ}_{F})\ensuremath{\ll}N$, where ${\mathrm{\ensuremath{\Delta}}}_{0}$ is the gap amplitude and ${ϵ}_{F}$ is the Fermi energy. We demonstrate that the difference between the $p+ip$ -wave SF and the other chiral SFs in the BCS regimes originates from the nature of edge modes and related depairing effects.We study the orbital angular momentum (OAM) ${L}_{z}$ in two-dimensional chiral $({p}_{x}+i{p}_{y}{)}^{\ensuremath{\nu}}$-wave superfluids (SFs) of $N$ fermions on a disk at zero temperature, in terms of spectral asymmetry and spectral flow. It is shown that ${L}_{z}=\ensuremath{\nu}N/2$ for any integer $\ensuremath{\nu}$, in the Bose-Einstein condensation regime. In contrast, in the BCS limit, while the OAM is ${L}_{z}=N/2$ for the $p+ip$-wave SF, for chiral SFs with $\ensuremath{\nu}\ensuremath{\ge}2$, the OAM is remarkably suppressed as ${L}_{z}=N\ifmmode\times\else\texttimes\fi{}O({\mathrm{\ensuremath{\Delta}}}_{0}/{ϵ}_{F})\ensuremath{\ll}N$, where ${\mathrm{\ensuremath{\Delta}}}_{0}$ is the gap amplitude and ${ϵ}_{F}$ is the Fermi energy. We demonstrate that the difference between the $p+ip$-wave SF and the other chiral SFs in the BCS regimes originates from the nature of edge modes and related depairing effects.

arXiv:1409.7459Physical Review LettersMay 13, 201568 citations

We show that the high temperature behavior of atomic gases near Feshbach Resonance with non-zero orbital angular momentum

(\ell >0)

belong to a universality class different from that of s-wave resonances. The universal interaction energy is

2(2\ell +1)

times larger than that of the s-wave when approaching the resonance from the atomic side, but is essentially zero on the molecular side; contrary to s-wave resonances where interaction energies on both sides are the same except for a sign change. The measurement of these universality properties should be feasible in current experiments.

We study the orbital angular momentum (OAM)

{L}_{z}

in two-dimensional chiral $({p}_{x}+i{p}_{y}{)}^{\ensuremath{\nu}}$-wave superfluids (SFs) of

N

fermions on a disk at zero temperature, in terms of spectral asymmetry and spectral flow. It is shown that ${L}_{z}=\ensuremath{\nu}N/2$ for any integer $\ensuremath{\nu}$, in the Bose-Einstein condensation regime. In contrast, in the BCS limit, while the OAM is

{L}_{z}=N/2

for the

p+ip

-wave SF, for chiral SFs with $\ensuremath{\nu}\ensuremath{\ge}2$, the OAM is remarkably suppressed as ${L}_{z}=N\ifmmode\times\else\texttimes\fi{}O({\mathrm{\ensuremath{\Delta}}}_{0}/{ϵ}_{F})\ensuremath{\ll}N$, where ${\mathrm{\ensuremath{\Delta}}}_{0}$ is the gap amplitude and

{ϵ}_{F}

is the Fermi energy. We demonstrate that the difference between the

p+ip

-wave SF and the other chiral SFs in the BCS regimes originates from the nature of edge modes and related depairing effects.