Description

2011/11/25, Prof. Roland Winkler

Place:  Sala de Seminarios del Departamento de Física Teórica e Historia de la Ciencia
Time: 12h
Title: Oscillatory multiband dynamics of free particles: The ubiquity of zitterbewegung effects
 
 
Abstract
  In the Dirac theory for the motion of free relativistic electrons,
highly oscillatory components appear in the time evolution of
physical observables such as position, velocity, and spin angular
momentum. This effect known as zitterbewegung (German for quivering
motion) is commonly considered to be a quirk of the otherwise very
successful Dirac theory of relativistic electron dynamics. Its
physical significance has been discussed controversially over the
years.

I will demonstrate that rather different solid-state systems with
gapped and/or spin-split energy spectrum exhibit analogs of
zitterbewegung as a common feature. It is also shown that many
features of zitterbewegung are shared by the simple and well-known
Landau Hamiltonian describing the dynamics of two-dimensional
electron systems in the presence of a magnetic field perpendicular
to the plane.

I will review various aspects of Zitterbewegung phenomena and link
the latter with observable effects such as electric-field-controllable spin precession and spin-dependent magnetic focusing.