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arXiv · 1111.1173

Scale invariance and viscosity of a two-dimensional Fermi gas

Enrico Vogt·Michael Feld·Bernd Fröhlich·Daniel Pertot·Marco Koschorreck·Michael Köhl
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Abstract

We investigate the collective excitations of a harmonically trapped two-dimensional Fermi gas from the collisionless (zero sound) to the hydrodynamic (first sound) regime. The breathing mode, which is sensitive to the equation of state, is observed at a frequency two times the dipole mode frequency for a large range of interaction strengths and temperatures, and the amplitude of the breathing mode is undamped. This provides evidence for a dynamical SO(2,1) scaling symmetry of the two-dimensional Fermi gas. Moreover, we investigate the quadrupole mode to measure the shear viscosity of the two-dimensional gas and study its temperature dependence.

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Enrico Vogt, Michael Feld, Bernd Fröhlich, Daniel Pertot, Marco Koschorreck, Michael Köhl. 2012-02-20. Scale invariance and viscosity of a two-dimensional Fermi gas. https://doi.org/10.1103/physrevlett.108.070404

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