# CMT Seminar: The Bose-glass phase in ladder systems

Monday, March 22, 2010 – 3:15pm

Reiss 261A

Juan F. Carrasquilla

International School of Advanced Studies (SISSA)

I will discuss the properties o the disordered Bose-Hubbard model on quasi-one-dimensional (ladder) systems, emphasizing the fact that this geometry is very useful to understand the evolution of the physical properties from one to two spatial dimensions. Moreover, experiments with both cold atomic gases and magnetic systems are becoming now possible on ladders and our calculations represent an important benchmark in this direction. From a direct calculation of the chemical potential, we construct the distribution probability of the gap on finite sizes, which contain useful information on different phases, e.g., superfluid, Bose glass, and Mott insulator. We clarify the structure of the excitations in the Bose-glass phase, where a broad distribution for the gap is present on finite clusters. Results on the local density across the superfluid to Bose-glass transition are also shown.

Host: Marcos Rigol