ISBN 9783843927413

978-3-8439-2741-3, Reihe Physik

Astrid Elisa Niederle
Local Aspects of the Bose Glass – Phase transitions of the disordered Bose–Hubbard model

189 Seiten, Dissertation Universität des Saarlandes, Saarbrücken (2016), Hardcover, A5

Zusammenfassung / Abstract

In a disordered optical lattice, filled with bosons, the Bose glass phase can occur. Interpreting this phase as a mixture of Mott insulator and superfluid sites, leads to an innovative criterion for all occurring phase transitions, called local mean-field cluster analysis, excellently agreeing with quantum Monte-Carlo results. Generalizing the Bose-Hubbard model to quasi-periodic potentials, as used in experiments, we showed that not only disorder in the depth of the lattice sites, but also in the tunneling rates contributes crucially to the phase diagram of quasi-periodic potentials. Moreover, the interplay of an optical lattice and a cavity field of photons leads to a density dependent potential for the bosons. In the parameter regime also accessible in experiments, the supersolid phase occurs additionally, which is characterized by a checker board pattern in the density profile.