近日，美国哥伦比亚大学的Sebastian Will及其研究团队取得一项新进展。经过不懈努力，他们观察到偶极分子玻色-爱因斯坦凝聚现象。相关研究成果已于2024年6月3日在国际权威学术期刊《自然》上发表。

本文报道了成功实现偶极分子玻色-爱因斯坦凝聚（BEC）的突破。通过增强碰撞屏蔽技术，研究人员有效抑制了二体和三体损失，成功将钠-铯分子蒸发冷却至量子简并状态，并跨越相变形成BEC。当相空间密度超过1时，BEC呈现出独特的双峰分布特征。此次实验中，BEC的冷凝分数达到60(10)%，温度低至6(2)nK，并且稳定寿命接近2秒。这项工作为探索迄今为止无法进入的区域中的偶极量子物质打开了大门，有望在光学晶格中生成奇异的偶极液滴，自组织晶体相和偶极自旋液体。

据悉，受量子力学定律支配的粒子系综表现出有趣的涌现行为。量子材料中的原子量子气体、液氦和电子由于它们的组成和相互作用都表现出不同的性质。超冷偶极分子的量子简并样品有望实现物质的新相，并为量子模拟和量子计算提供新的途径。然而，尽管采用了碰撞屏蔽技术来减少快速损失，但这一方法迄今为止仍然阻碍了实现蒸发冷却至玻色-爱因斯坦凝聚（BEC）的过程。

附：英文原文

Title: Observation of Bose–Einstein condensation of dipolar molecules

Author: Bigagli, Niccolo, Yuan, Weijun, Zhang, Siwei, Bulatovic, Boris, Karman, Tijs, Stevenson, Ian, Will, Sebastian

Issue&Volume: 2024-06-03

Abstract: Ensembles of particles governed by quantum mechanical laws exhibit intriguing emergent behaviour. Atomic quantum gases, liquid helium and electrons in quantum materials all exhibit distinct properties because of their composition and interactions. Quantum degenerate samples of ultracold dipolar molecules promise the realization of new phases of matter and new avenues for quantum simulation and quantum computation. However, rapid losses, even when reduced through collisional shielding techniques, have so far prevented evaporative cooling to a Bose–Einstein condensate (BEC). Here we report on the realization of a BEC of dipolar molecules. By strongly suppressing two- and three-body losses via enhanced collisional shielding, we evaporatively cool sodium–caesium molecules to quantum degeneracy and cross the phase transition to a BEC. The BEC reveals itself by a bimodal distribution when the phase-space density exceeds 1. BECs with a condensate fraction of 60(10)% and a temperature of 6(2)nK are created and found to be stable with a lifetime close to 2s. This work opens the door to the exploration of dipolar quantum matter in regimes that have been inaccessible so far, promising the creation of exotic dipolar droplets, self-organized crystal phases and dipolar spin liquids in optical lattices.

DOI: 10.1038/s41586-024-07492-z

Source: https://www.nature.com/articles/s41586-024-07492-z