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Updated: Jul 13, 2026
11:21
Cooling an Optically Trapped Ultracold Fermi Gas by Periodical Driving
Published on: March 30, 2017
Negative echo in the density evolution of ultracold fermionic gases
F Fumarola1, Y Ahmadian, I L Aleiner
1Physics Department, Columbia University, New York, New York 10027, USA.
Physical Review Letters
|August 7, 2007
Summary
We predict a novel nonequilibrium critical phenomenon in fermionic gases. A negative echo in density evolution may help locate the superfluid transition temperature.
Area of Science:
- Quantum physics
- Condensed matter physics
- Ultracold atomic gases
Background:
- Superfluidity in fermionic systems is a key area of research.
- Understanding the Bose-Einstein condensation-BCS crossover is crucial for quantum gases.
- Nonequilibrium dynamics in quantum systems are not fully understood.
Purpose of the Study:
- To predict a novel nonequilibrium critical phenomenon in fermionic gases.
- To investigate the space-time density evolution of a fermionic gas above the superfluid transition temperature.
- To explore the Bose-Einstein condensation-BCS crossover dynamics.
Main Methods:
- Theoretical prediction of a critical phenomenon.
- Analysis of space-time density evolution.
- Study of localized density disturbances in a fermionic gas.
Main Results:
- A negative echo in density evolution was predicted on the BCS side of the crossover.
- This echo competes with bosonic molecule spreading near the BEC side.
- The echo dominates at later times, even near the BEC side.
Conclusions:
- A nonequilibrium critical phenomenon, characterized by a negative echo, is predicted.
- This phenomenon can serve as an experimental tool to locate the superfluid transition.
- The findings offer new insights into the dynamics of quantum gases across the BEC-BCS crossover.
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