Breadcrumb
How do wave packets spread? Time evolution on Ehrenfest time scales.
Fri 25 January 2013, 14:00
Roman Schubert
University of Bristol
Organiser: Nina Snaith
ABSTRACT
We derive an extension of the standard time dependent WKB theory which can be applied to
propagate coherent states and other strongly localised states for long times. It allows in particular
to give a uniform description of the transformation from
a localised coherent state to a delocalised Lagrangian state which takes place at the Ehrenfest time.
The main new ingredient is a metaplectic operator which is used to modify the initial state in a way that
standard time dependent WKB can then be applied for the propagation. This is joint work
with Fabricio Toscano and Raul Vallejos.