Van der Waals-Zeeman Institute, Institute of Physics, University of Amsterdam, Amsterdam, the Netherlands.
Institute for Theoretical Physics, Institute of Physics, University of Amsterdam, Amsterdam, the Netherlands.
Nature. 2022 Jun;606(7915):683-687. doi: 10.1038/s41586-022-04731-z. Epub 2022 Jun 8.
Bose-Einstein condensates (BECs) are macroscopic coherent matter waves that have revolutionized quantum science and atomic physics. They are important to quantum simulation and sensing, for example, underlying atom interferometers in space and ambitious tests of Einstein's equivalence principle. A long-standing constraint for quantum gas devices has been the need to execute cooling stages time-sequentially, restricting these devices to pulsed operation. Here we demonstrate continuous Bose-Einstein condensation by creating a continuous-wave (CW) condensate of strontium atoms that lasts indefinitely. The coherent matter wave is sustained by amplification through Bose-stimulated gain of atoms from a thermal bath. By steadily replenishing this bath while achieving 1,000 times higher phase-space densities than previous works, we maintain the conditions for condensation. Our experiment is the matter wave analogue of a CW optical laser with fully reflective cavity mirrors. This proof-of-principle demonstration provides a new, hitherto missing piece of atom optics, enabling the construction of continuous coherent-matter-wave devices.
玻色-爱因斯坦凝聚态（Bose-Einstein condensates，BECs）是一种宏观相干物质波，它彻底改变了量子科学和原子物理学。BECs 在量子模拟和传感方面非常重要，例如，它是太空原子干涉仪和爱因斯坦等效原理雄心勃勃的测试的基础。长期以来，量子气体设备一直受到需要按时间顺序执行冷却阶段的限制，这限制了这些设备只能进行脉冲操作。在这里，我们通过创建持续时间无限的锶原子连续波（continuous-wave，CW）凝聚态来证明连续玻色-爱因斯坦凝聚态的实现。相干物质波通过从热浴中受激放大原子而得到持续放大。通过不断补充这种热浴，同时实现比以前的工作高 1000 倍的相空间密度，我们维持了凝聚的条件。我们的实验是具有全反射腔镜的连续波光学激光的物质波模拟，这一原理验证性的演示提供了原子光学中一个全新的、迄今为止缺失的部分，使连续相干物质波器件的构建成为可能。
