Skip to main content
U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Laser Cooling Without Repumping: A Magneto-Optical Trap for Erbium Atoms



Jabez J. McClelland, James L. Hanssen


We report on a novel mechanism that allows for laser cooling of atoms that do not have a closed cycling transition. This mechanism is observed in a magneto-optical trap for erbium, an atom with a very complex energy level structure with multiple pathways for optical pumping losses. We observe surprisingly high trap populations of over 106 atoms and densities of over 1011 atoms cm-3, despite the many potential loss channels. A model based on recycling of metastable and ground state atoms held in the quadrupole magnetic field of the trap explains the high trap population, and agrees well with time-dependent measurements of MOT fluorescence. The demonstration of trapping of a rare-earth atom such as erbium opens a wide range of new possibilities for practical applications and fundamental studies with cold atoms.
Physical Review Letters




McClelland, J. and Hanssen, J. (2006), Laser Cooling Without Repumping: A Magneto-Optical Trap for Erbium Atoms, Physical Review Letters (Accessed May 18, 2024)


If you have any questions about this publication or are having problems accessing it, please contact

Created April 14, 2006, Updated February 19, 2017