Cold collisions of atoms and molecules

Measurements of interactions between cold molecules and ultracold atoms can allow for a detailed understanding of fundamental collision processes. These measurements can be done using various experimental geometries, including where both species are in a beam, where one species is trapped, or when both species are trapped. Simultaneous trapping offers significantly longer interaction times and an associated increased sensitivity to rare collision events. However, there are significant practical challenges associated with combining atomic and molecular systems, which often have competing experimental requirements. Here, we describe in detail an experimental system that allows for studies of cold collisions between ultracold atoms and cold molecules in a dual trap, where the atoms and molecules are trapped using static magnetic and electric fields, respectively. As a demonstration of the system's capabilities, we study cold collisions between ammonia ( $^{14}\mathrm{ND}_{3}$ and $^{15}\mathrm{ND}_{3}$ ) molecules and rubidium ( $^{87}\mathrm{Rb}$ and $^{85}\mathrm{Rb}$ ) atoms.Measurements of interactions between cold molecules and ultracold atoms can allow for a detailed understanding of fundamental collision processes. These measurements can be done using various experimental geometries, including where both species are in a beam, where one species is trapped, or when both species are trapped. Simultaneous trapping offers significantly longer interaction times and an associated increased sensitivity to rare collision events. However, there are significant practical challenges associated with combining atomic and molecular systems, which often have competing experimental requirements. Here, we describe in detail an experimental system that allows for studies of cold collisions between ultracold atoms and cold molecules in a dual trap, where the atoms and molecules are trapped using static magnetic and electric fields, respectively. As a demonstration of the system's capabilities, we study cold collisions between ammonia ($^{14}\mathrm{ND}_{3}$ and $^{15}\mathrm{ND}_{3}$) molecules and rubidium ($^{87}\mathrm{Rb}$ and $^{85}\mathrm{Rb}$) atoms.

arXiv:2001.02317Physical Review AMar 16, 20209 citations

Theory of Cold Atomic and Molecular Collisions

Jeremy M. Hutson

CRC Press eBooksJun 25, 20093 citations

Cold collisions between atoms and diatomic molecules

Marius Lysebo, Leif Veseth

Collision cross sections are calculated for the three systems ${\text{O}}_{2}\text{-He}$ , ${\text{Na}}_{2}\text{-Na}$ and ${\text{K}}_{2}\text{-K}$ at cold and ultracold temperatures. We discuss their relevance for cold molecule formation by buffer-gas cooling and by other cooling methods where collisions between molecules and atoms are important, e.g photoassociation. The molecule is treated as a rigid rotator in the electronic and vibrational ground state. We have calculated ab initio the potential energy surfaces for the three systems with special emphasis on the long range potential which is very important at low energies. With relevance to buffer gas cooling, we have also studied the thermalization process between ${\text{O}}_{2}$ molecules and He atoms as determined by the calculated cross sections.Collision cross sections are calculated for the three systems ${\text{O}}_{2}\text{-He}$, ${\text{Na}}_{2}\text{-Na}$ and ${\text{K}}_{2}\text{-K}$ at cold and ultracold temperatures. We discuss their relevance for cold molecule formation by buffer-gas cooling and by other cooling methods where collisions between molecules and atoms are important, e.g photoassociation. The molecule is treated as a rigid rotator in the electronic and vibrational ground state. We have calculated ab initio the potential energy surfaces for the three systems with special emphasis on the long range potential which is very important at low energies. With relevance to buffer gas cooling, we have also studied the thermalization process between ${\text{O}}_{2}$ molecules and He atoms as determined by the calculated cross sections.

Physical Review AMar 24, 200815 citations

Cold molecules, collisions and reactions

Johannes Hecker Denschlag

Bulletin of the American Physical SocietyMay 26, 20160 citations

^{14}\mathrm{ND}_{3}

and

^{15}\mathrm{ND}_{3}

) molecules and rubidium (

^{87}\mathrm{Rb}

and

^{85}\mathrm{Rb}

) atoms.

Collision cross sections are calculated for the three systems

{\text{O}}_{2}\text{-He}

{\text{Na}}_{2}\text{-Na}

and

{\text{K}}_{2}\text{-K}

at cold and ultracold temperatures. We discuss their relevance for cold molecule formation by buffer-gas cooling and by other cooling methods where collisions between molecules and atoms are important, e.g photoassociation. The molecule is treated as a rigid rotator in the electronic and vibrational ground state. We have calculated ab initio the potential energy surfaces for the three systems with special emphasis on the long range potential which is very important at low energies. With relevance to buffer gas cooling, we have also studied the thermalization process between

{\text{O}}_{2}

molecules and He atoms as determined by the calculated cross sections.