|
A two day workshop
on recent progress in graphene and topological
insulators is planned by and held at IPM,
Tehran. This workshop is intended to provide
advanced research information about the on-going
activities in the hottest subjects in
contemporary physics and materials science.
Graphene is a newly realized two-dimensional
(2D) electron system which has engendered a
great deal of interest because of the new
physics which it exhibits and because of its
potential as a new material for electronic
technology. In this 2D electron system, states
near the Fermi energy of a graphene sheet are
described by a massless Dirac equation which has
chiral band states in which the honeycomb-sublattice
pseudo-spin is aligned either parallel to or
opposite to the envelope function momentum. In
graphene, the physics of relativistic electrons
is now experimentally accessible in solid-state
devices, whose behavior differs drastically from
that of similar devices fabricated with common
semiconductors. Consequently, new unexpected
phenomena have been observed, and phenomena that
are well understood in common semiconductors
–such as the quantum Hall effect or
weak-localization- exhibit surprising
differences in graphene. Graphene device allows
simulating in solid-state experiments some
subtle and previously unreachable effects from
high-energy physics, such as Klein tunneling and
vacuum breakdown. At the same time, graphene is
considered as a perspective material for
'post-silicon electronics', and the first
graphene transistors were already created and
studied. Being both transparent and highly
conducting, graphene has a very high potential
for use in optical devices. Chemical, mechanical
and other properties of graphene also open new
ways for numerous important applications. It is
not surprising therefore than graphene became
one of the hottest subjects in contemporary
physics and materials science and the number of
publications in the field, including top-level
scientific journals, as well as the number of
researchers involved, grew exponentially.
Furthermore, certain insulators exhibit metallic
states on their surfaces. The 2D topological
insulator is a quantum spin Hall insulator,
which is a close relation of the integer Quantum
Hall State. A 3D topological insulator supports
novel spin polarized 2D Dirac fermions on its
surface. |
