Dear Friends,
On Thursday, January 24, there will be an ITAMP topical lunch discussion.
Tea Room (P-226) @ CfA (60 Garden Street)
Time: 12:00-1:30
As always pizza will be served.
Speaker: Michael Knap
Title: Time dependent impurities in ultracold quantum gases:
exploring universal quantum dynamics
Abstract:
The physics of impurities in metals and mesoscopic structures provided a
deeper understanding of electrical and thermal transport properties,
guided the development of new mathematical techniques, and gave useful
insights into the behavior of more complicated strongly correlated
materials.
Ensembles of ultracold atoms offer new opportunities to study impurity
physics in a well isolated, coherent setting with relatively slow time
scales, that can be faithfully determined by a small number of precisely
controllable parameters, and come with a rich experimental toolbox
allowing for a detailed characterization of the system. In this talk, we
outline a program of how to explore quantum impurity problems with
ultracold atoms. In particular, we reconsider the classic problem of the
orthogonality catastrophe, which describes the dynamics of a localized
impurity in a Fermi sea. We present its complete solution, discover new
qualitative features which could not be observed in metallic systems,
and discuss the effect of interactions.
In the second part of this talk we study fast impurities in correlated
quantum gases, which feature a novel collective state manifesting for
example in coherent oscillations of the impurity momentum – a phenomenon
known as quantum flutter. We demonstrate the existence of quantum
flutter beyond integrability, which suggests that its physics is of
universal character.
Looking forward to seeing you there,
Misha Lemeshko
--
Dr. Mikhail Lemeshko
Institute for Theoretical Atomic, Molecular, and Optical Physics (ITAMP)
Harvard-Smithsonian Center for Astrophysics MS-14
60 Garden St.
Cambridge, MA 02138
U.S.A.
mlemeshko(a)cfa.harvard.edu
http://sites.google.com/site/mishalemeshko/
Tel. +1 (617) 496-7610
Fax +1 (617) 496-7668