Stability of quantum degenerate fermionic polar molecules without and with microwave shielding*

A stabilization of a fermionic molecular gas towards collapse in attractive head-to-tail collisions and its evaporative cooling below the Fermi temperature has so far been achieved in two ways. Either a strong dc electric field is applied to confine the molecular motion to 2D [1] or inelastic collisions in 3D are strongly suppressed by applying a circularly polarized microwave field [2]. Here we use a Hartree-Fock mean-field theory [3,4] in order to determine the 3D properties of quantum degenerate fermionic molecules. In particular, we compare the stability diagrams occurring without (with) microwave shielding, where a (negative) dipole-dipole interaction is present. In case that the orientation of the electric dipoles with respect to the trap axes is unknown, we outline how to reconstruct it from time-of-flight absorption measurements.

[1] G. Valtolina, et al., Nature 588, 239 (2020).

[2] A. Schindewolf, et al., arXiv:2201.05143 (2022).

[3] V. Veljic, et al., New J. Phys. 20, 093016 (2018).

[4] V. Veljic, A. Pelster, and A. Balaz, Phys. Rev. Res. 1, 012009 (2019).