It is known from the solution of the two-body problem that an anisotropic dipolar interaction can give rise to s-wave scattering resonances, which are named dipolar interaction induced resonances (DIIR). In this Letter, we study the zero-temperature many-body physics of a two-component Fermi gas across a DIIR. In the low-density regime, it is very striking that the resulting pairing order parameter is a nearly isotropic singlet pairing and the physics can be well described by an s-wave resonant interaction potential with finite range conditions, despite the anisotropic nature of the dipolar interaction. The pairing energy is as strong as a unitary Fermi gas near a magnetic Feshbach resonance. In the high-density regime, the anisotropic effect plays an important role. We find phase transitions from singlet pairing to a state with mixed singlet and triplet pairing and then from mixed pairing to pure triplet pairing. The state with mixed pairing spontaneously breaks the time-reversal symmetry.It is known from the solution of the two-body problem that an anisotropic dipolar interaction can give rise to s-wave scattering resonances, which are named dipolar interaction induced resonances (DIIR). In this Letter, we study the zero-temperature many-body physics of a two-component Fermi gas across a DIIR. In the low-density regime, it is very striking that the resulting pairing order parameter is a nearly isotropic singlet pairing and the physics can be well described by an s-wave resonant interaction potential with finite range conditions, despite the anisotropic nature of the dipolar interaction. The pairing energy is as strong as a unitary Fermi gas near a magnetic Feshbach resonance. In the high-density regime, the anisotropic effect plays an important role. We find phase transitions from singlet pairing to a state with mixed singlet and triplet pairing and then from mixed pairing to pure triplet pairing. The state with mixed pairing spontaneously breaks the time-reversal symmetry.

arXiv:1208.5419Physical Review LettersJan 24, 201318 citations

Pairing in Fermion Systems

S. Mazumdar

Physical Review LettersNov 30, 19872 citations

Roton-assisted chiral p -wave superfluid in a quasi-two-dimensional dipolar Bose-Fermi quantum-gas mixture

Ben Kain, Hong Yuan Ling

The chiral $p$ -wave (${p}_{x}\ifmmode\pm\else\textpm\fi{}i{p}_{y}$) superfluid has attracted significant attention in recent years, mainly because its vortex core supports a Majorana fermion which, due to its non-Abelian statistics, can be explored for implementing topological quantum computation. Mixing dipolar bosons with fermions in quasi-two-dimensional space offers the opportunity to use the roton minimum as a tool for engineering the phonon-induced attractive interaction between fermions. We study, within the Hartree-Fock-Bogoliubov approach, the $p$ -wave superfluid pairings in a quasi-two-dimensional dipolar Bose-Fermi mixture. We show that enhancing the induced interaction by lowering the roton minimum can affect the stability property of the mixture as well as the effective mass of the fermions in an important way. We also show that one can tune the system to operate in stable regions where chiral $p$ -wave superfluid pairings can be resonantly enhanced by lowering the energy cost of the phonons near the roton minimum.The chiral $p$-wave (${p}_{x}\ifmmode\pm\else\textpm\fi{}i{p}_{y}$) superfluid has attracted significant attention in recent years, mainly because its vortex core supports a Majorana fermion which, due to its non-Abelian statistics, can be explored for implementing topological quantum computation. Mixing dipolar bosons with fermions in quasi-two-dimensional space offers the opportunity to use the roton minimum as a tool for engineering the phonon-induced attractive interaction between fermions. We study, within the Hartree-Fock-Bogoliubov approach, the $p$-wave superfluid pairings in a quasi-two-dimensional dipolar Bose-Fermi mixture. We show that enhancing the induced interaction by lowering the roton minimum can affect the stability property of the mixture as well as the effective mass of the fermions in an important way. We also show that one can tune the system to operate in stable regions where chiral $p$-wave superfluid pairings can be resonantly enhanced by lowering the energy cost of the phonons near the roton minimum.

arXiv:1309.1139Physical Review ASep 16, 20130 citations

One-dimensional fermion pairing

Rafael Mendoza, MANUEL DE LLANO, Mauricio Fortes +1 more

Bulletin of the American Physical SocietyMar 11, 20080 citations

Stability and collapse of fermions in a binary dipolar boson-fermion 164 Dy- 161 Dy mixture

Sadhan K. Adhikari

We suggest a time-dependent mean-field hydrodynamic model for a binary dipolar boson-fermion mixture to study the stability and collapse of fermions in the ${}^{164}$ Dy- ${}^{161}$ Dy mixture. The condition of stability of the dipolar mixture is illustrated in terms of phase diagrams. A collapse is induced in a disk-shaped stable binary mixture by jumping the interspecies contact interaction from repulsive to attractive by the Feshbach resonance technique. The subsequent dynamics is studied by solving the time-dependent mean-field model including three-body loss due to molecule formation in boson-fermion and boson-boson channels. Collapse and fragmentation in the fermions after subsequent explosions are illustrated. The anisotropic dipolar interaction leads to anisotropic fermionic density distribution during collapse. This study is carried out in three-dimensional space using realistic values of dipolar and contact interactions.We suggest a time-dependent mean-field hydrodynamic model for a binary dipolar boson-fermion mixture to study the stability and collapse of fermions in the ${}^{164}$Dy-${}^{161}$Dy mixture. The condition of stability of the dipolar mixture is illustrated in terms of phase diagrams. A collapse is induced in a disk-shaped stable binary mixture by jumping the interspecies contact interaction from repulsive to attractive by the Feshbach resonance technique. The subsequent dynamics is studied by solving the time-dependent mean-field model including three-body loss due to molecule formation in boson-fermion and boson-boson channels. Collapse and fragmentation in the fermions after subsequent explosions are illustrated. The anisotropic dipolar interaction leads to anisotropic fermionic density distribution during collapse. This study is carried out in three-dimensional space using realistic values of dipolar and contact interactions.

arXiv:1305.1604Physical Review AOct 3, 20137 citations

The chiral

p

-wave (${p}_{x}\ifmmode\pm\else\textpm\fi{}i{p}_{y}$) superfluid has attracted significant attention in recent years, mainly because its vortex core supports a Majorana fermion which, due to its non-Abelian statistics, can be explored for implementing topological quantum computation. Mixing dipolar bosons with fermions in quasi-two-dimensional space offers the opportunity to use the roton minimum as a tool for engineering the phonon-induced attractive interaction between fermions. We study, within the Hartree-Fock-Bogoliubov approach, the

p

-wave superfluid pairings in a quasi-two-dimensional dipolar Bose-Fermi mixture. We show that enhancing the induced interaction by lowering the roton minimum can affect the stability property of the mixture as well as the effective mass of the fermions in an important way. We also show that one can tune the system to operate in stable regions where chiral

p

-wave superfluid pairings can be resonantly enhanced by lowering the energy cost of the phonons near the roton minimum.

We suggest a time-dependent mean-field hydrodynamic model for a binary dipolar boson-fermion mixture to study the stability and collapse of fermions in the

{}^{164}

Dy-

{}^{161}

Dy mixture. The condition of stability of the dipolar mixture is illustrated in terms of phase diagrams. A collapse is induced in a disk-shaped stable binary mixture by jumping the interspecies contact interaction from repulsive to attractive by the Feshbach resonance technique. The subsequent dynamics is studied by solving the time-dependent mean-field model including three-body loss due to molecule formation in boson-fermion and boson-boson channels. Collapse and fragmentation in the fermions after subsequent explosions are illustrated. The anisotropic dipolar interaction leads to anisotropic fermionic density distribution during collapse. This study is carried out in three-dimensional space using realistic values of dipolar and contact interactions.