Prospects for thermalization of microwave-shielded ultracold molecules

• Main Authors: Wang, Reuben R. W, Bohn, John L
• Format: Journal Article
• Language: English
• Published: 26.10.2023
• Subjects: Physics - Quantum Gases; Physics - Quantum Physics
• DOI: 10.48550/arxiv.2310.17812

We study anisotropic thermalization in dilute gases of microwave shielded polar molecular fermions. For collision energies above the threshold regime, we find that thermalization is suppressed due to a strong preference for forward scattering and a reduction in total cross section with energy, significantly reducing the efficiency of evaporative cooling. We perform close-coupling calculations on the effective potential energy surface derived by Deng et al. [Phys. Rev. Lett. 130, 183001 (2023)], to obtain accurate 2-body elastic differential cross sections across a range of collision energies. We use Gaussian process regression to obtain a global representation of the differential cross section, over a wide range of collision angles and energies. The route to equilibrium is then analyzed with cross-dimensional rethermalization experiments, quantified by a measure of collisional efficiency toward achieving thermalization.