Condensed Matter Seminar, Stephan Mandt, "Transport and non-equilibrium dynamics in optical lattices: from expanding atomic clouds to negative absolut
Ultracold atoms in optical lattices offer the possibility of exploring
transport properties of model Hamiltonians,
such as the fermionic Hubbard model.
However, here we emphasize that cold atoms
can also behave very differently from solids:
being e.g. exposed to a gravitational force, a cloud of interacting cold atoms in an optical lattice
does not simply "fall downwards".
Driven by internal heat currents,
it expands symmetrically upwards and downwards, while
its radius R grows as R ~ t^1/3 in time. We also
discuss related non-equilibrium processes and the emergence of
negative absolute temperatures in optical lattices.
References:
U. Schneider et al., Nature Physics (2012)
Mandt, Rapp and Rosch, Phys. Rev. Lett. 106, 250602 (2011)
Rapp, Mandt and Rosch, Phys. Rev. Lett. 105, 220405 (2010)
Location: PCTS Seminar Room
Date/Time: 04/02/12 at 1:15 pm - 04/02/12 at 2:30 pm
Category: Condensed Matter Seminar
Department: Physics