IQC Colloquium featuring Sebastian Will, Columbia University

Sebastian Will, Columbia University

Ultracold dipolar molecules feature strong long-range interactions and have long been envisioned as a powerful platform for many-body quantum physics. However, cooling molecules to quantum degeneracy has remained a major experimental challenge for more than two decades. 

We have now created the first Bose-Einstein condensate (BEC) of dipolar molecules [1]. Via evaporative cooling, we bring a gas of sodium-cesium molecules to temperatures below 10 nanokelvin, deep into the quantum degenerate regime, and observe lifetimes of several seconds. This is enabled by collisional shielding via microwave dressing, suppressing molecular losses by four orders of magnitude [2]. Microwave dressing also provides an exceptional level of control over dipole-dipole interactions, opening the door to novel phases of matter in molecular quantum liquids. Most recently, we have observed the formation of self-bound droplets in a strongly dipolar molecular BEC [3].  

In this talk, I will describe our experimental approach, discuss recent results, and give an outlook on new opportunities enabled by molecular BECs for quantum simulation, quantum computing, and many-body quantum physics. In addition, I will briefly highlight our broader efforts in quantum, including recent advances in single-atom trapping in metasurface optical tweezer arrays [4]. 

References: 

[1] Bigagli, Yuan, Zhang, et al., Observation of Bose-Einstein condensation of dipolar molecules, Nature 631, 289-293 (2024) 

[2] Yuan, Zhang, et al., Extreme loss suppression in an ultracold molecular gas with widely tunable dipolar interactions, Science, 393, 1226-1229 (2026) 

[3] Zhang, Yuan, et al., Observation of self-bound droplets of ultracold dipolar molecules, Nature, 651,601-606 (2026) 

[4] Holman, Xu, et al., Trapping of single atoms in metasurface optical tweezer arrays, Nature, 649, 859-865 (2026)