Losses, Many‐Body Correlations, and Universality in Ultracold Molecules

Abstract

Recent experimental developments have allowed physicists to freeze molecules' motion down to an ultracold temperature regime where quantum effects become profound. Furthermore, each molecule can be precisely prepared at chosen internal states and the mutual interactions between molecules are also highly tunable. As such, ultracold molecules have emerged as a powerful platform in multiple disciplines across physics and chemistry. Meanwhile, a grand challenge exists as to how losses of molecules depend on a quantum many-body environment. In this article, the recent experimental and theoretical progress of exploring losses of ultracold molecules is reviewed. Since the conventional theoretical scheme of treating isolated pairs of molecules is no longer applicable to the quantum degenerate regime that has been reached in recent experiments, an alternative framework of universal relations between two-body losses and many-body correlations has been established. Regardless of microscopic parameters ranging from the temperature and the particle number to the interaction strength, these universal relations always hold. This approach unfolds a simple universality behind complex loss processes of many-body systems and provides physicists and chemists with a new tool to explore ultracold molecules. OverviewThe realization of Bose-Einstein condensates in laboratories has brought physicists to an ultracold world in which intriguing quantum phenomena arise in a temperature regime down to a few nano-Kelvin. [1,2] In the past many years, a vast range of important quantum states and quantum phenomena have been accessed and explored in the field of quantum gases. [3][4][5][6][7][8][9][10][11][12] While the study of ultracold atoms continues to prosper, a new platform