Talk by Philip Hofmann: Surface electronic structure of topological insulators

Surface electronic structure of topological insulators

The discovery of materials with entirely new properties is
one of the most fascinating aspects of physics, and such findings have
always played a major role in human development and culture. A very
recent example of conceptually new materials are the so-called
topological insulators. On the face of it, these are well-known,
off-the-shelf materials, but they have a previously overlooked and
profound "topological" property which forces their surfaces and edges
to be metallic, in contrast to the insulating bulk. Moreover, the
one-dimensional (two-dimensional) metal at the edge (surface) of a
topological insulator was shown to be inherently robust against
disturbances, and to possess special transport properties linked to
the electron's spin. The first example of a topological insulator
appeared in the quantum spin Hall effect which was discovered in 2007.
Since then, several materials were shown to be topological insulators
and new ones are reported every few weeks. Also, many theoretical
suggestions were made on how to exploit the special properties of the
surface metals, e.g. for the formation of hitherto elusive particles
or for applications in spintronics and quantum computing.

In this talk, I will explain the basic physics of topological
insulators, establish a connection to the research on surfaces state
with strong spin orbit splitting and try to convey the fascination of
this field. I will also discuss our recent results on the electronic
structure and electron dynamics of the prototypical topological
insulator Bi2Se3.