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Cooling an Optically Trapped Ultracold Fermi Gas by Periodical Driving
Published on: March 30, 2017
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Hydrodynamic Relaxation in a Strongly Interacting Fermi Gas
Xin Wang1, Xiang Li1, Ilya Arakelyan1
1Department of Physics, North Carolina State University, Raleigh, North Carolina 27695, USA.
Physical Review Letters
|March 18, 2022
Summary
Researchers measured the decay of a density profile in a strongly interacting Fermi gas. This allowed direct measurement of thermal conductivity and shear viscosity from the fluid
Area of Science:
- Quantum fluids
- Condensed matter physics
- Ultracold atomic gases
Background:
- Strongly interacting Fermi gases are crucial for understanding quantum phenomena.
- Previous methods for measuring transport properties like thermal conductivity and shear viscosity were indirect.
Purpose of the Study:
- To directly measure thermal conductivity and shear viscosity.
- To investigate the dynamics of a spatially periodic density profile in a Fermi gas.
Main Methods:
- Confining a strongly interacting Fermi gas in a box potential.
- Creating a spatially periodic density profile in thermal equilibrium.
- Measuring the free decay of the dominant spatial Fourier component after perturbation removal.
Main Results:
- Observed both a thermally diffusive (exponentially decaying) mode and a first sound (decaying oscillatory) mode.
- Successfully decoupled and independently measured thermal conductivity and shear viscosity.
Conclusions:
- The free decay of a density profile provides a direct route to measure transport coefficients.
- This method offers a powerful tool for characterizing strongly interacting quantum fluids.
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