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arXiv · 1908.04495

Frustrated orbital Feshbach resonances in a Fermi gas

E. K. Laird·Z. -Y. Shi·M. M. Parish·J. Levinsen
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Abstract

The orbital Feshbach resonance (OFR) is a novel scheme for magnetically tuning the interactions in closed-shell fermionic atoms. Remarkably, unlike the Feshbach resonances in alkali atoms, the open and closed channels of the OFR are only very weakly detuned in energy. This leads to a unique effect whereby a medium in the closed channel can Pauli block, or frustrate, the two-body scattering processes. Here, we theoretically investigate the impact of frustration in the few- and many-body limits of the experimentally accessible three-dimensional $^{173}$Yb system. We find that by adding a closed-channel atom to the two-body problem, the binding energy of the ground state is significantly suppressed, and by introducing a closed-channel Fermi sea to the many-body problem, we can drive the system towards weaker fermion pairing. These results are potentially relevant to superconductivity in solid-state multiband materials, as well as to the current and continuing exploration of unconventional Fermi-gas superfluids near the OFR.

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E. K. Laird, Z. -Y. Shi, M. M. Parish, J. Levinsen. 2019-08-13. Frustrated orbital Feshbach resonances in a Fermi gas. https://doi.org/10.1103/physreva.101.022707

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