Collisionally induced laser cooling of ultradense molecular gases

虽然激光冷却原子是一种非常成功的技术，但迄今为止，这种分子冷却仍然是一个难以捉摸的目标。这个项目的目的是实验证明激光冷却超致密分子气体。我们将使用一种技术，这是补充早期的方法，并使用激光诱导的过渡在高压环境中，频繁的分子缓冲气体碰撞转移分子跃迁到共振与一个高度红色失谐的激光束，而自发衰减发生接近未扰动的过渡频率。在这样的激发循环中，我们期望从探针系综中提取动能和内部分子能量。在初步的实验中，我们的小组已经成功地证明了碰撞再分配冷却的超致密原子系综与铷原子和230巴的氩气缓冲气体。由于复杂的振动和分子结构，其在高压缓冲气体环境中的特性仍有待研究，再分配冷却的分子的应用需要密集的研究。我们预见再分配冷却在分子量子物理学和一种新型化学中的诱人应用。其他应用可以包括光学冷却器。

While laser cooling of atoms is a very successful technique, such cooling of molecules has so far been an elusive goal. The aim of this project is to experimentally demonstrate the laser cooling of an ultradense molecular gas. We will use a technique that is complementary to earlier approaches and uses laser-induced transitions in a high pressure environment, with frequent molecule-buffer gas collisions shifting molecular transitions into resonance with a highly red detuned laser beam, while spontaneous decay occurs close to the unperturbed transition frequency. In such excitation cycles, we expect kinetic and internal molecular energy to be extracted from the probe ensemble. In preliminary experiments, our group has successfully demonstrated collisional redistribution cooling for an ultradense atomic ensemble with rubidium atoms and 230 bar of argon buffer gas. Due to the complex vibrational and molecular structure, whose characteristics in a high pressure buffer gas environment remain to be investigated, the application of redistribution cooling to molecules requires intense research. We foresee tantalizing applications of redistribution cooling in molecular quantum physics and a novel type of chemistry. Other applications can include optical chillers.