Triplet pair amplitude in a trapped $s$-wave superfluid Fermi gas with broken spin rotation symmetry. II. Three dimensional continuum case

Abstract

We extend our recent work [Y. Endo et. al., Phys. Rev. 92, 023610 (2015)] for a parity-mixing effect in a model two-dimensional lattice fermions to a realistic three-dimensional ultracold Fermi gas. Including effects of broken local spatial inversion symmetry by a trap potential within the framework of the real-space Bogoliubov-de Gennes theory at $T=0$, we point out that an odd-parity $p$-wave Cooper-pair amplitude is expected to have already been realized in previous experiments on an (even-parity) $s$-wave superfluid Fermi gas with spin imbalance. This indicates that, when one suddenly changes the $s$-wave pairing interaction to an appropriate $p$-wave one by using a Feshbach technique in this case, a non-vanishing $p$-wave superfluid order parameter is immediately obtained, which is given by the product of the $p$-wave interaction and the $p$-wave pair amplitude that has already been induced in the spin-imbalanced $s$-wave superfluid Fermi gas. Thus, by definition, the system is in the $p$-wave superfluid state, at least just after this manipulation. Since the achievement of a $p$-wave superfluid state is one of the most exciting challenges in cold Fermi gas physics, our results may provide an alternative approach to this unconventional pairing state. In addition, since the parity-mixing effect cannot be explained as far as one deals with a trap potential in the local density approximation (LDA), it is considered as a crucial example which requires us to go beyond LDA.

20 pages, 7 figures

References in corpus (16)

• Spin-Injection Spectroscopy of a Spin-Orbit Coupled Fermi Gas
• Collective excitations of a degenerate gas at the BEC-BCS crossover
• A Bose-Einstein Condensate in a Uniform Light-induced Vector Potential
• Phase diagram of a two-component Fermi gas with resonant interactions
• Exploring an ultracold Fermi-Fermi mixture: Interspecies Feshbach resonances and scattering properties of 6Li and 40K
• Quantum degenerate two-species Fermi-Fermi mixture coexisting with a Bose-Einstein condensate
• p-wave Feshbach molecules
• Chiral Rashba spin textures in ultra-cold Fermi gases
• Three fully polarized fermions close to a p-wave Feshbach resonance
• Fermion Superfluids of Non-Zero Orbital Angular Momentum near Resonance
• Stability of the fermionic gases close to a p-wave Feshbach resonance
• Strongly-resonant p-wave superfluids
• Thermodynamics of a Trapped Unitary Fermi Gas
• Thermodynamics of a trapped unitary Fermi gas
• Superfluid shells for trapped fermions with mass and population imbalance
• Hetero pairing and component-dependent pseudogap phenomena in an ultracold Fermi gas with mass imbalance