Resonance-facilitated three-channel p-wave scattering

Abstract

Feshbach resonances of arbitrary width are typically described in terms of two-channel models. Within these models, one usually considers a single dressed resonance, with the option to extend the analysis by including resonant open-channel features that can drastically change the observed threshold effects. For the strong ${}^{40}\mathrm{K}$ p-wave resonance studied in Ref. \cite{ahmed2021}, the interplay between an open-channel shape resonance and the Feshbach resonance could explain the unexpected nonlinear variation of the binding energy with magnetic field. However, the presented two-channel treatment relies on the introduction of two independent fitting parameters, whereas the typical Breit-Wigner expression would only account for one. This results in an effective magnetic moment that acquires a nonphysical value, which is an indication of a major shortcoming of the two-channel model treatment. In this study, we observe how the presence of a closed-channel shape resonance explains the physical mechanism behind the observations and demonstrates the need of a three-channel treatment. We introduce our novel model as \textit{resonance facilitated}, where all coupling is mediated by the Feshbach state, while there is no direct coupling between the additional channel and the open channel. Notably, the resonance-facilitated structure greatly reduces the complexity of the full three-channel model. The typical Breit-Wigner form of the two-channel Feshbach formalism is retained and the full effect of the added channel can be captured by a single resonance dressing factor, which describes how the free propagation in the Feshbach state is dressed by the added channel.

References in corpus (14)

• Observation of Bose-Einstein Condensation of Molecules
• Quantum Computation Using Vortices and Majorana Zero Modes of a $p_x$ + $i{p}_y$ Superfluid of Fermionic Cold Atoms
• p-wave Feshbach molecules
• Many-body theory of excitation dynamics in an ultracold Rydberg gas
• Binding Energies of 6Li p-wave Feshbach Molecules
• Stability of the fermionic gases close to a p-wave Feshbach resonance
• Universal van der Waals Physics for Three Ultracold Atoms
• Large-momentum distribution of a polarized Fermi gas and p-wave contacts
• Two-body relaxation in a Fermi gas at a p-wave Feshbach resonance
• Three-Body Recombination in One Dimension
• Comparative study of one-dimensional Bose and Fermi gases with contact interactions from the viewpoint of universal relations for correlation functions
• Stretching p-wave molecules by transverse confinements
• Microscopy of an ultranarrow Feshbach resonance using a laser-based atom collider: A quantum defect theory analysis
• Loosely Bound Few-Body States in a Spin-1 Gas with Near-Degenerate Continua