10,495 research outputs found
Spectral stability of Prandtl boundary layers: an overview
In this paper we show how the stability of Prandtl boundary layers is linked
to the stability of shear flows in the incompressible Navier Stokes equations.
We then recall classical physical instability results, and give a short
educational presentation of the construction of unstable modes for Orr
Sommerfeld equations. We end the paper with a conjecture concerning the
validity of Prandtl boundary layer asymptotic expansions.Comment: 17 page
Fractionalization of minimal excitations in integer quantum Hall edge channels
A theoretical study of the single electron coherence properties of Lorentzian
and rectangular pulses is presented. By combining bosonization and the Floquet
scattering approach, the effect of interactions on a periodic source of voltage
pulses is computed exactly. When such excitations are injected into one of the
channels of a system of two copropagating quantum Hall edge channels, they
fractionalize into pulses whose charge and shape reflects the properties of
interactions. We show that the dependence of fractionalization induced
electron/hole pair production in the pulses amplitude contains clear signatures
of the fractionalization of the individual excitations. We propose an
experimental setup combining a source of Lorentzian pulses and an Hanbury Brown
and Twiss interferometer to measure interaction induced electron/hole pair
production and more generally to reconstruct single electron coherence of these
excitations before and after their fractionalization.Comment: 18 pages, 10 figures, 1 tabl
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