Mobile impurities and Greens function measurements in strongly correlated atoms: advances through strong numerics

by Adrian Kantian (Univ. de Geneve)

Wednesday 3 Dec 2014, 11:15 → 12:15 Europe/Zurich

EPFL, 727 du BSP

Advances in ultracold-gas physics are enabling experiments involving the direct manipulation
and observation of single- or few-atom mobile impurities [1,2] within a many-body quantum system, a topic of longstanding interest for condensed matter theory, where it is related to studies of e.g. conductivity and the X-ray edge problem. In light of these developments we study the dynamics of a single distinguishable mobile impurity in 1D quantum liquids, combining DMRG numerics with analytical techniques. We show that the recently described subdiffusive regime of impurity motion [3] actually constitutes universal behaviour, one that is fundamentally different from the naively expected quasiparticle dynamics [4]. This work is extended to the important issue of measuring timedependent Greens-functions and higher-order correlators in-situ for strongly correlated atoms in optical lattices [5].
[1] PRA 85, 023623 (2012)
[2[ Nature Physics 9, 235 (2013)
[3] PRL 99, 240404 (2007); PRL 103, 110401 (2009)
[4[ PRL 113, 070601 (2014)
[5[ PRL 111, 147205 (2013)