Colloquia 2005
Electronic
Phenomena in One Dimensional GaAs Channels
Professor
Michael Pepper, FRS
Cavendish Laboratory
University of Cambridge
Date
4-5 p.m., Thursday,
17 March, 2005
Location
School of Physics
Common Room
Room 64 Old Main Building
The University of New South Wales
Abstract
In this talk a survey will be given on some of our recent work on electron
transport in one-dimension in GaAs channels formed by "electrostatic
squeezing". A parallel magnetic field can induce a crossing of
opposite spin levels which appears to give rise to an interaction and
the discontinuous appearance of a new level. It is possible that this
is part of a series occurring whenever spin levels cross and the 0.7
feature is the first in this series to be formed. In sufficiently long
channels it is found that for particular values of carrier concentration,
and temperature, electrons are trapped in a non-conducting state below
the conduction band and eventually the system is completely non-conducting
characterised by a gap at the Fermi energy. Finally results will be
presented on the spin interactions between electrons and nuclei and,
in particular, it will be shown that the observed behaviour provides
strong evidence for the spin polarisation of electrons in the absence
of a magnetic field.
The audience,
including graduate students, are invited to meet the speaker 15 minutes
beforehand over wine and cheese in the Physics Common Room.
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