Deborah S. Jin

Jin was born in Santa Clara County, California,[12] Jin was one of three children, and grew up in Indian Harbour Beach, Florida.[13] Her father was a physicist and her mother a physicist working as an engineer.[13] Her father Ron Jin was born in Fuzhou in 1933 and passed away in 2010.[14]

Jin graduated magna cum laude from Princeton University in 1990, receiving an A.B. in physics after completing a senior thesis titled "A Condensation-Pumped Dilution Refrigerator for Use in Cooling Millimeter Wave Bolometer Detectors".[15][5][16] She was a recipient of the Allen G. Shenstone Prize in Physics in 1990.

Jin then studied at the University of Chicago, where she was a NSF Graduate Fellow from 1990 to 1993 and received a Ph.D. in physics in 1995, completing a doctoral thesis titled "Experimental Study of the Phase Diagrams of Heavy Fermion Superconductors with Multiple Transitions" under the supervision of Thomas Felix Rosenbaum.[17]

After completing her Ph.D., Jin joined Eric Cornell's group at JILA, the Joint Institute for Laboratory Astrophysics in Boulder, Colorado, as a postdoctoral researcher. This change from condensed matter to atomic physics required her to learn a new set of experimental techniques. Jin joined Cornell's group soon after they achieved the first rubidium Bose-Einstein condensate (BEC), and performed experiments characterizing its properties.[18]

In 1997, Jin formed her own group at JILA. Within two years, she developed the ability to create the first quantum degenerate gas of fermionic atoms. The work was motivated by earlier studies of BEC's and the ability to cool a dilute gas of atoms to 1 μK. The weak interactions between particles in a BEC led to interesting physics. It was theorized that fermionic atoms would form an analogous state at low enough temperatures, with fermions pairing up in a phenomenon similar to the creation of Cooper pairs in superconducting materials.[19]

The work was complicated by the fact that, unlike bosons, fermions cannot occupy the same quantum state at the same time, due to the Pauli exclusion principle, and are therefore limited with regard to cooling mechanisms. At low enough temperature evaporative cooling, an important technique used to reach low enough temperature to create the first BEC's, is no longer effective for fermions. To circumvent this issue, Jin and her team cooled potassium-40 atoms in two different magnetic sublevels. This enabled atoms in different sublevels to collide with each other, restoring the efficacy of evaporative cooling. Using this technique, Jin and her group were able to produce a degenerate Fermi gas at a temperature of about 300 nK, or half the Fermi temperature of the mixture.[20][21]

In 2003, Jin and her team were the first to condense pairs of fermionic atoms. They directly observed a molecular Bose-Einstein condensate created solely by adjusting the interaction strength in an ultracold Fermi gas of atoms using a Feshbach resonance. She was able to observe transitions of the gas between a Bardeen-Cooper-Schrieffer (BCS) state and Bose-Einstein condensate.[22]

In 2008, Jin and her team developed a technique analogous to angle-resolved photoemission spectroscopy (ARPES) which allowed them to measure excitations of their degenerate gas with both energy- and momentum-resolution. They used this approach to study the nature of fermion pairing across the BCS-BEC crossover, the same system her group had first explored in 2003.[23] These experiments provided the first experimental evidence of a pseudogap in the BCS-BEC crossover.[24]

Jin continued to advance the frontiers of ultracold science when she and her colleague, Jun Ye, managed to cool polar molecules that possess a large electric dipole moment to ultracold temperatures, also in 2008. Rather than directly cool polar molecules, they created a gas of ultracold atoms and then transformed them into dipolar molecules in a coherent way. This work led to novel insights regarding the chemical reactions near absolute zero. They were able to observe and control potassium-rubidium (KRb) molecules in the lowest energy state (ground state). They were even able to observe molecules colliding and breaking and forming chemical bonds.[25] Jin's husband, John Bohn, who specialized in the theory of ultracold atomic collisions, collaborated with her on this work.