We study a one-dimensional (1D) two-component atomic Fermi gas with an infinite intercomponent contact repulsion. It is found that adding an attractive nearly resonant odd-wave interaction breaking the rotational symmetry one can make the ground state ferromagnetic. A promising system for the observation of this itinerant ferromagnetic state is a 1D gas of $^{40}\mathrm{K}$ atoms, where three dimensional $s$ -wave and $p$ -wave Feshbach resonances are very close to each other and the 1D confinement significantly reduces the inelastic decay.We study a one-dimensional (1D) two-component atomic Fermi gas with an infinite intercomponent contact repulsion. It is found that adding an attractive nearly resonant odd-wave interaction breaking the rotational symmetry one can make the ground state ferromagnetic. A promising system for the observation of this itinerant ferromagnetic state is a 1D gas of $^{40}\mathrm{K}$ atoms, where three dimensional $s$-wave and $p$-wave Feshbach resonances are very close to each other and the 1D confinement significantly reduces the inelastic decay.

arXiv:1512.01392Physical Review AJul 5, 201621 citations

Theory of spinor Fermi and Bose gases in tight atom waveguides

Marvin D. Girardeau, Maxim Olshanii

Divergence-free pseudo-potentials for spatially even- and odd-wave interactions in spinor Fermi gases in tight atom waveguides are derived. The Fermi-Bose mapping method is used to relate the effectively one-dimensional fermionic many-body problem to that of a spinor Bose gas. Depending on the relative magnitudes of the even- and odd-wave interactions, the $N$ -atom ground state may have total spin $S=0$ , $S=N∕2$ , and possibly also intermediate values, the case $S=N∕2$ applying near a $p$ -wave Feshbach resonance, where the $N$ -fermion ground state is space-antisymmetric and spin-symmetric. In this case the fermionic ground state maps to the spinless bosonic Lieb-Liniger gas. An external magnetic field with a longitudinal gradient causes a Stern-Gerlach spatial separation of the corresponding trapped Fermi gas with respect to various values of ${S}_{z}$ .Divergence-free pseudo-potentials for spatially even- and odd-wave interactions in spinor Fermi gases in tight atom waveguides are derived. The Fermi-Bose mapping method is used to relate the effectively one-dimensional fermionic many-body problem to that of a spinor Bose gas. Depending on the relative magnitudes of the even- and odd-wave interactions, the $N$-atom ground state may have total spin $S=0$, $S=N∕2$, and possibly also intermediate values, the case $S=N∕2$ applying near a $p$-wave Feshbach resonance, where the $N$-fermion ground state is space-antisymmetric and spin-symmetric. In this case the fermionic ground state maps to the spinless bosonic Lieb-Liniger gas. An external magnetic field with a longitudinal gradient causes a Stern-Gerlach spatial separation of the corresponding trapped Fermi gas with respect to various values of ${S}_{z}$.

arXiv:cond-mat/0401402Physical Review AAug 23, 200481 citations

The one-dimensional Fermi gas

Hanoch Gutfreund

Annals of the Israel Physical SocietyJan 1, 19780 citations

^{40}\mathrm{K}

atoms, where three dimensional

s

-wave and

p

-wave Feshbach resonances are very close to each other and the 1D confinement significantly reduces the inelastic decay.

N

-atom ground state may have total spin

S=0

S=N∕2

, and possibly also intermediate values, the case

S=N∕2

applying near a

p

-wave Feshbach resonance, where the

N

-fermion ground state is space-antisymmetric and spin-symmetric. In this case the fermionic ground state maps to the spinless bosonic Lieb-Liniger gas. An external magnetic field with a longitudinal gradient causes a Stern-Gerlach spatial separation of the corresponding trapped Fermi gas with respect to various values of

{S}_{z}