Аннотация:
Massless Dirac fermions, the charge carriers in graphene and topological
insulators, have very unusual properties. One of the most striking
phenomena they exhibit is Klein tunneling: an electron normally incident
on an electrostatic potential barrier will always be transmitted. This
is in stark contrast to conventional Schrцdinger particles, for which
the transmission is exponentially small. In this talk, I will discuss
scattering of two-dimensional massless Dirac fermions by a
one-dimensional potential in detail. In particular, I will show that
there are three different regimes of scattering. For each of these
regimes, I will show how the transmission for a generic potential
barrier can be obtained by using the semiclassical
(Wentzel-Kramers-Brillouin) approximation. The predictions provided by
our analytic expressions show good agreement with numerical calculations
for all considered cases. This talk is based on work that was done
together with Mikhail Katsnelson and Timur Tudorovskiy.
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