We describe the ro-vibrational van der Waals interaction between ultracold polar molecules. This interaction is strong, leading to fast elastic collisions and orders of magnitude suppression of collisional loss. This enables evaporative cooling of Fermi mixtures of molecules in different ro-vibrational states, without active shielding by applying external fields. The scheme is compatible with microwave shielding, where it enables controlled state dependent interactions, opening up new opportunities for quantum simulation and impurity physics. The interaction can also be used to stabilize fermionic molecules in optical lattices, to control interactions in synthetic dimensions, for enhanced tweezer loading, and direct infrared shielding.We describe the ro-vibrational van der Waals interaction between ultracold polar molecules. This interaction is strong, leading to fast elastic collisions and orders of magnitude suppression of collisional loss. This enables evaporative cooling of Fermi mixtures of molecules in different ro-vibrational states, without active shielding by applying external fields. The scheme is compatible with microwave shielding, where it enables controlled state dependent interactions, opening up new opportunities for quantum simulation and impurity physics. The interaction can also be used to stabilize fermionic molecules in optical lattices, to control interactions in synthetic dimensions, for enhanced tweezer loading, and direct infrared shielding.

cond-mat.quant-gasCross-listedarXiv:2607.25774Jul 29, 20260 citations

Nonlinear optics with polar molecules in optical lattices

T. Bragdon, E. I. Kuznetsova, Susanne F. Yelin

Bulletin of the American Physical SocietyMay 23, 20090 citations

Electric field suppression of ultracold confined chemical reactions

Goulven Quéméner, John L. Bohn

We consider ultracold collisions of polar molecules confined in a one-dimensional optical lattice. Using a quantum scattering formalism and a frame transformation method, we calculate elastic and chemical quenching rate constants for fermionic molecules. Taking $^{40}\mathrm{K}$ $^{87}\mathrm{Rb}$ molecules as a prototype, we find that the rate of quenching collisions is enhanced at zero electric field as the confinement is increased but that this rate is suppressed when the electric field is turned on. For molecules with 500 nK of collision energy, for realistic molecular densities, and for achievable experimental electric fields and trap confinements, we predict lifetimes for KRb molecules to be $1$ s. We find a ratio of elastic to quenching collision rates of about $100$ , which may be sufficient to achieve efficient evaporative cooling of polar KRb molecules.We consider ultracold collisions of polar molecules confined in a one-dimensional optical lattice. Using a quantum scattering formalism and a frame transformation method, we calculate elastic and chemical quenching rate constants for fermionic molecules. Taking $^{40}\mathrm{K}$$^{87}\mathrm{Rb}$ molecules as a prototype, we find that the rate of quenching collisions is enhanced at zero electric field as the confinement is increased but that this rate is suppressed when the electric field is turned on. For molecules with 500 nK of collision energy, for realistic molecular densities, and for achievable experimental electric fields and trap confinements, we predict lifetimes for KRb molecules to be $1$ s. We find a ratio of elastic to quenching collision rates of about $100$, which may be sufficient to achieve efficient evaporative cooling of polar KRb molecules.

arXiv:1003.4026Physical Review AJun 9, 201066 citations

^{40}\mathrm{K}

^{87}\mathrm{Rb}

molecules as a prototype, we find that the rate of quenching collisions is enhanced at zero electric field as the confinement is increased but that this rate is suppressed when the electric field is turned on. For molecules with 500 nK of collision energy, for realistic molecular densities, and for achievable experimental electric fields and trap confinements, we predict lifetimes for KRb molecules to be

1

s. We find a ratio of elastic to quenching collision rates of about

100

, which may be sufficient to achieve efficient evaporative cooling of polar KRb molecules.