Optimized multichannel quantum defect theory for cold molecular collisions

Croft, James F.E.; Hutson, Jeremy M.; Julienne, Paul S.

Abstract

Multichannel quantum defect theory (MQDT) can provide an efficient alternative to full coupled-channel calculations for low-energy molecular collisions. However, the efficiency relies on interpolation of the Y matrix that encapsulates the short-range dynamics, and there are poles in Y that may prevent interpolation over the range of energies of interest for cold molecular collisions. We show how the phases of the MQDT reference functions may be chosen so as to remove such poles from the vicinity of a reference energy and dramatically increase the range of interpolation. For the test case of Mg+NH, the resulting optimized Y matrix may be interpolated smoothly over an energy range of several Kelvin and a magnetic field range of over 1000 gauss. Calculations at additional energies and fields can then be performed at a computational cost that is proportional to the number of channels N and not to N3.

Citation

Croft, J. F., Hutson, J. M., & Julienne, P. S. (2012). Optimized multichannel quantum defect theory for cold molecular collisions. Physical Review A, 86(2), Article 022711. https://doi.org/10.1103/physreva.86.022711

• Journal Article Type: Article
• Publication Date: Jan 1, 2012
• Deposit Date: Jun 19, 2013
• Publicly Available Date: Jun 28, 2013
• Journal: Physical Review A - Atomic, Molecular, and Optical Physics
• Print ISSN: 1050-2947
• Electronic ISSN: 1094-1622
• Publisher: American Physical Society
• Peer Reviewed: Peer Reviewed
• Volume: 86
• Issue: 2
• Article Number: 022711
• DOI: https://doi.org/10.1103/physreva.86.022711
• Public URL: https://durham-repository.worktribe.com/output/1481724