Talk by Philip Hofmann – Niels Bohr Institute - University of Copenhagen

Niels Bohr Institute > Calendar > 2011 > Talk by Philip Hofmann

Talk by Philip Hofmann

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.