The polaronic effect of a metal layer on variable range hopping

by Mr. Ofek Asban

at Condensed Matter Seminar

Mon, 26 Oct 2020, 11:30
Zoom

Abstract

*** Zoom only see details below ***

We investigate the effect of a metal plate on the variable range hopping (VRH) conductivity of a
two dimensional electron-glass (EG) system. The VRH conductivity is known to have a stretched
exponential dependence on temperature, with an exponent p that depends on the shape of the EG's
single particle density of states (DOS). For constant DOS p = 1/3 and for linear DOS p = 1/2,
also known as Mott's and Efros-Shklovskii's VRH respectively. The presence of the plate causes
two effects on the EG system, static and dynamic. The well known static effect accounts for the
additional screening of the Coulomb repulsion in the EG and for the partial filling of the Coulomb
gap in the DOS. This in turn causes an increase of the conductivity at very low temperatures. Here we investigate the complementary dynamical effect, which is related to the polaronic phenomena.
Our main result is the dynamical suppression of the standard phonon assisted hopping and, thus,
suppression of the conductivity in a much wider range of temperatures as compared to the low
temperature static effect. The relation to experiments is discussed.



Dganit Meidan is inviting you to a scheduled Zoom meeting.

Topic: Condensed matter seminar-Ofek Asban
Time: Oct 26, 2020 11:30 AM Jerusalem

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Created on 12-10-2020 by Meidan, Dganit (dganit)
Updaded on 19-10-2020 by Meidan, Dganit (dganit)