Advanced Search

Browse by Discipline

Scientific Societies

E-print Alerts

Add E-prints

E-print Network

  Advanced Search  

Condensed Matter Colloquium Thursday, April 7, 2011

Summary: Condensed Matter Colloquium
Thursday, April 7, 2011
2 pm, Room 1201
Refreshments at 1:30 pm in Room 1305F
Nuh Gedik
Massachusetts Institute of Technology
Probing the Topological Insulators with Ultrashort Laser Pulses
Topological insulator (TI) is a new phase of matter that exhibits quantum-Hall-like
properties, even in the absence of an external magnetic field. Charge carriers on
the surface of a TI behave like a two-dimensional gas of massless helical Dirac
fermions in which the spin is locked perpendicular to the momentum.
Understanding and characterizing unique properties of these materials can lead to
novel applications such as current induced magnetization or extremely robust
quantum memory bits. In this talk, I will give a brief overview of this field and
discuss recent experiments in which we used ultrafast laser pulses to probe the
fascinating properties of these systems. In particular, I will present our recent
measurements in which we simultaneously mapped all three components of spin
over the entire Dirac cone of a TI by using circularly polarized ultrafast laser pulses
to perform novel time-of-flight based angle-resolved photoelectron spectroscopy. I
will show that an idealized description of helical Dirac fermions only applies within


Source: Appelbaum, Ian - Department of Physics, University of Maryland at College Park


Collections: Engineering; Materials Science