Jeudi 10 janvier 2013 à 10h15
Salle 234, Ecole de Physique

Impurities in trapped one-dimensional quantum liquids

Julius Bonart, Université Pierre et Marie Curie, France

Recent experiments with cold atoms on impurity dynamics immersed in trapped 1D quantum liquids have revealed an interesting interplay between the dynamic polaronic impurity mass shift and the renormalization of the optical potential. We show that the influence of the external trap on the Bose gas leads to a steeper effective potential for the impurity. We propose a framework in which this potential renormalization and the mass shift can be quantitatively understood by using a semi-classical theory of density wave excitations in the Luttinger liquid. Then we present more rigorous results on the impurity dynamics which are obtained via the nonequilibrium formalism of a quantum Brownian particle. We show that the obtained theoretical results reproduce well recent experimental data.