Hannover 2020 – wissenschaftliches Programm
Die DPG-Frühjahrstagung in Hannover musste abgesagt werden! Lesen Sie mehr ...
SYQL 1.4: Hauptvortrag
Donnerstag, 12. März 2020, 12:30–13:00, e415
The birth of a degenerate Fermi gas of molecules — •Jun Ye — JILA, NIST and University of Colorado
It is an honor to help celebrate the scientific legacy of Prof. Eberhard Tiemann. I wish to elaborate an important role Prof. Tiemann played during the early stages of the first experiment in producing a high phase-space density gas of polar molecules in the absolute ground state. The experiment was jointly performed with my late colleague Prof. Deborah Jin in 2008, and we received invaluable theory guidance from Profs. Tiemann, Julienne, and Kotochigova.
With this successful approach of making ultracold molecules, we observed for the first time that molecular collisions and chemical reactions are controlled via quantum statistics and single collisional partial waves. When molecules are loaded in a 3D optical lattice, a spin lattice system is formed where many-body spin dynamics are controlled by long-range and anisotropic dipolar interactions.
In 2018 we finally produced the first degenerate Fermi gas of polar molecules, with up to 100,000 KRb molecules and T/T_F as low as 0.3. Density fluctuations in the degenerate molecular gas are observed to be sub-Poissonian, and confirm its full thermalization. To control molecular interactions, we use microwave fields and large DC electric fields with adjustable gradients. By confining the molecules in a 2D geometry, we observe a strong suppression of chemical reaction loss and an increase of the molecular phase-space-density via evaporative cooling. This sets the stage to discover new insights to strongly correlated quantum systems and chemistry in the quantum regime.