Microwave shielding

Collisional loss is a fundamental challenge in ultracold molecular gases. When molecules collide, they can be lost from the trap, making it difficult to maintain a dense, stable gas and preventing efficient evaporative cooling. We proposed collisional shielding using microwaves to engineer repulsive interactions between molecules and thereby suppress collisional loss.

Since then, we have continued to develop microwave shielding. In particular, double microwave shielding strongly suppresses both collisional loss and three-body recombination, enabling exceptionally stable, dense molecular quantum gases. Collisional shielding has become an important enabling technique for reaching quantum-degenerate molecular gases.

We now use these capabilities to explore new regimes of many-body physics and quantum technologies with molecules. The combination of long-lived, dense molecular gases and quantum degeneracy opens opportunities for quantum simulation and for studying strongly interacting quantum systems, while also bringing new questions about how shielding itself can be extended and improved.