Quantum Defect Theory for Orbital Feshbach Resonance

Abstract

In the ultracold gases of alkali-earth (like) atoms, a new type of Feshbach resonance, i.e., the orbital Feshbach resonance (OFR), has been proposed and experimentally observed in ultracold ${}^{173}$Yb atoms. When the OFR of the ${}^{173}$Yb atoms occurs, the energy gap between the open and closed channels is smaller by two orders of magnitudes than the van der Waals energy. As a result, quantitative accurate results for the low-energy two-body problems can be obtained via multi-channel quantum defect theory (MQDT), which is based on the exact solution of the Schr$\ddot{\mathrm{o}}$dinger equation with the van der Waals potential. In this paper we use the MQDT to calculate the two-atom scattering length, effective range, and the binding energy of two-body bound states for the systems with OFR. With these results we further study the clock-transition spectrum for the two-body bound states, which can be used to experimentally measure the binding energy. Our results are helpful for the quantitative theoretical and experimental researches for the ultracold gases of alkali-earth (like) atoms with OFR.

11 pages, 6 figuers

References in corpus (5)

• Spectroscopic observation of SU(N)-symmetric interactions in Sr orbital magnetism
• Observation of two-orbital spin-exchange interactions with ultracold SU(N)-symmetric fermions
• Direct observation of coherent inter-orbital spin-exchange dynamics
• Universal relations of strongly interacting Fermi gases with multiple scattering channels
• Dissociation of Feshbach molecules via spin-orbit coupling in ultracold Fermi gases