ISBN 978-3-8439-3058-1

978-3-8439-3058-1, Reihe Physik

Christoph Ölschläger
Floquet Engineering of Bloch Bands in Shaken Optical Lattices

129 Seiten, Dissertation Universität Hamburg (2016), Softcover, B5

Zusammenfassung / Abstract

In recent years, ultracold quantum gases in optical lattices have imposingly proven to serve as quantum simulators for condensed matter phenomena and beyond. Increasing effort has been spent to develop elaborate tools for engineering, manipulating and probing exotic quantum many-body states. In this context, time-periodic driving constitutes a powerful technique and is subsumed under the term Floquet engineering.

In this thesis bosonic ensembles in driven optical lattices are employed to engineer and systematically study novel and complex band structures. In particular, time-periodic inertial forces are created by accelerating the lattice potential, whereas the resulting effective Bloch bands are calculated by means of Floquet theory.

This work covers three central topics. The first part discusses the remarkable structures of dressed Bloch bands in a triangular lattice that arise due to coherent coupling. The second part is devoted to the experimental creation and study of artificial gauge potentials for neutral atoms in optical lattices. In the triangular lattice, this allows for the emulation of a classical Ising-XY spin model. In the final part of this thesis, multiphoton absorption processes - up to the 9th order - between different Bloch bands are observed and investigated.