Marco Beria, Yasir Iqbal, Massimiliano Di Ventra, Markus Müller
While classical or quantum interacting liquids become turbulent under sufficiently strong driving, it is not obvious what flow pattern an ideal quantum gas develops under similar conditions. Unlike classical non-interacting particles which exhibit rather trivial flow, ideal fermions have to satisfy the exclusion principle, which acts as a form of collective repulsion. We thus study the flow of an ideal Fermi gas as it is driven out of a narrow orifice of width comparable to the Fermi wavelength, employing both a micro-canonical approach to transport, and solving a Lindblad equation for Markovian driving leads. Both methods are in good agreement and predict an out-flowing current density with a complex microscopic pattern of vorticity in the steady state. Applying a bias of the order of the chemical potential results in a short-range correlated antiferromagnetic vorticity pattern, corresponding to local moments of the order of a tenth of a magneton, $e\hbar/2m$, if the fermions are charged. The latter may be detectable by magneto-sensitive spectroscopy in strongly driven cold gases (atoms) or clean electronic nanostructures (electrons).
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http://arxiv.org/abs/1306.0422
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