Diatomic-py: A Python module for calculating the rotational and hyperfine structure of 1Σ molecules
Computer Physics Communications Elsevier 282 (2022) 108512
Abstract:
We present a computer program to calculate the quantised rotational and hyperfine energy levels of diatomic molecules in the presence of dc electric, dc magnetic, and off-resonant optical fields. Our program is applicable to the bialkali molecules used in ongoing state-of-the-art experiments with ultracold molecular gases. We include functions for the calculation of space-fixed electric dipole moments, magnetic moments and transition dipole moments.Program summary
Program Title: Diatomic-Py
CPC Library link to program files: https://doi.org/10.17632/3yfxnh5bn5.1
Developer's repository link: https://doi.org/10.5281/zenodo.6632148
Licensing provisions: BSD 3-clause
Programming language: Python ≥ 3.7
Nature of problem: Calculation of the rotational and hyperfine structure of molecules in the presence of dc magnetic, dc electric, and off-resonant laser fields.
Solution method: A matrix representation of the Hamiltonian is constructed in the uncoupled basis set. Eigenstates and eigenenergies are calculated by numerical diagonalization of the Hamiltonian.
Additional comments including restrictions and unusual features: Restricted to calculating the Stark and Zeeman shifts with co-axial electric and magnetic fields.
Diatomic-py: A python module for calculating the rotational and hyperfine structure of $^1Σ$ molecules
ArXiv 2205.05686 (2022)
[Data and analysis] Optimisation of scalable ion-cavity interfaces for quantum photonic networks
University of Oxford (2022)
Abstract:
Numerical data generated from python module available at DOI:10.5281/zenodo.7020047. Data are presented and analysed in arxiv 2112.05795Molecule-molecule and atom-molecule collisions with ultracold RbCs molecules
New Journal of Physics IOP Publishing 23 (2021) 125004
Abstract:
Understanding ultracold collisions involving molecules is of fundamental importance for current experiments, where inelastic collisions typically limit the lifetime of molecular ensembles in optical traps. Here we present a broad study of optically trapped ultracold RbCs molecules in collisions with one another, in reactive collisions with Rb atoms, and in nonreactive collisions with Cs atoms. For experiments with RbCs alone, we show that by modulating the intensity of the optical trap, such that the molecules spend 75% of each modulation cycle in the dark, we partially suppress collisional loss of the molecules. This is evidence for optical excitation of molecule pairs mediated via sticky collisions. We find that the suppression is less effective for molecules not prepared in the spin-stretched hyperfine ground state. This may be due either to longer lifetimes for complexes in the dark or to laser-free decay pathways. For atom–molecule mixtures, RbCs + Rb and RbCs + Cs, we demonstrate that the rate of collisional loss of molecules scales linearly with the density of atoms. This indicates that, in both cases, the loss of molecules is rate-limited by two-body atom–molecule processes. For both mixtures, we measure loss rates that are below the thermally averaged universal limit.Optimisation of Scalable Ion-Cavity Interfaces for Quantum Photonic Networks
ArXiv 2112.05795 (2021)