Robust control over intermolecular interactions is a key requirement for many emerging applications of ultracold polar molecules in chemical physics and quantum information science. I will present two general techniques for controlling two-body and many-body interactions in ultracold molecular gases. First, quantum interference of the different transition pathways enables extensive control over ultracold molecule-molecule collision cross sections [1]. Second, strong and tunable electric dipolar interactions can be used in a general protocol for on-demand generation of robust entangled states of nuclear and/or electron spins of ultracold polar molecules [2].

[1] A. Devolder, P. Brumer, and T. V. Tscherbul, Complete quantum coherent control of ultracold molecular collisions, Phys. Rev. Lett. 126, 153403 (2021).
[2] T. V. Tscherbul, J. Ye, and A. M. Rey, Robust nuclear spin entanglement via dipolar interactions in polar molecules, arXiv:2205.00190.