Observing S-Matrix Pole Flow in Resonance Interplay

Chilcott, Matthew; Gayen, Samyajit; Croft, James; Thomas, Ryan; Kjærgaard, Niels

Abstract

We provide an overview of experiments exploring resonances in the collision of ultracold clouds of atoms. Using a laser-based accelerator that capitalises on the energy resolution provided by the ultracold atomic setting, we unveil resonance phenomena such as Feshbach and shape resonances in their quintessential form by literally photographing the halo of outgoing scattered atoms. We exploit the tunability of magnetic Feshbach resonances to instigate an interplay between scattering resonances. By experimentally recording the scattering in a parameter space spanned by collision energy and magnetic field, we capture the imprint of the S-matrix pole flow in the complex energy plane. After revisiting experiments that place a Feshbach resonance in the proximity of a shape resonance and an anti-bound state, respectively, we discuss the possibility of using S-matrix pole interplay between two Feshbach resonances to create a bound-state-in-the-continuum.

Citation

Chilcott, M., Gayen, S., Croft, J., Thomas, R., & Kjærgaard, N. (2024). Observing S-Matrix Pole Flow in Resonance Interplay. Few-Body Systems, 65(2), Article 61. https://doi.org/10.1007/s00601-024-01930-4

• Journal Article Type: Article
• Acceptance Date: May 5, 2024
• Online Publication Date: May 25, 2024
• Publication Date: May 25, 2024
• Deposit Date: Jun 12, 2024
• Publicly Available Date: Jun 12, 2024
• Journal: Few-Body Systems
• Print ISSN: 0177-7963
• Electronic ISSN: 1432-5411
• Publisher: Springer
• Peer Reviewed: Peer Reviewed
• Volume: 65
• Issue: 2
• Article Number: 61
• DOI: https://doi.org/10.1007/s00601-024-01930-4
• Public URL: https://durham-repository.worktribe.com/output/2471608