Speaker
Prof.
Michael Pepper
(University College London, UK)
Description
Abstract: It will be shown that as the 1D confinement
potential is weakened the electron wavefunctions relax in
the second dimension and, in order to minimise the
electron-electron repulsion, an array is formed in which a
two row configuration is the ground state. This behaviour,
which is the prelude to formation of a Wigner Lattice, will be
discussed along with the spin incoherent regime. This arises
in the low carrier concentration limit when the exchange
energy between neighbouring electrons becomes small and
the spin direction can no longer be defined. The role of a
magnetic field on the formation of a two row ground state
will be discussed and results presented showing how it can
provide information on the magnitude of the interaction.
When the confinement is sufficiently weak filling the levels
with electrons can alter the normal sequence of the levels
so that the, (one-electron), first excited state now becomes
lower in energy than the normal ground state. Results will
be presented on these effects and how the electrostatically
defined order of the levels is altered by the electron-electron
interaction.
