Quantum gases in rotating optical lattices
Author(s)
Advisor
Oktel, Mehmet ÖzgürDate
2010Publisher
Bilkent University
Language
English
Type
ThesisItem Usage Stats
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Abstract
The thesis is structured into two main parts so as to cover bosons and
fermions in rotating optical lattices separately. In the first part, after a brief
introduction to ultracold atoms in optical lattices, we review the single-particle
physics for the lowest (s) band of a periodic potential under an artificial magnetic
field created by rotation. Next, we discuss rotational effects on the first
excited (p) band of the lattice, extending the methods available for the lowest
band. We conclude the first part with a discussion of many-body physics in
rotating lattice systems using a mean-field approach and investigate how the
transition boundary between superfluid and Mott insulator phases is affected
by the single-particle spectrum. In this context, we also examine a possible
coexistent phase of Mott insulator and bosonic fractional quantum Hall states,
appearing for certain system parameters near the Mott insulator lobes in the
phase diagram.
The second part starts with the proposal of a realization and detection
scheme for the so-called topological Hofstadter insulator, which basically reveals
the single-particle spectrum discussed before. The scheme depends on
a measurement of the density profile for noninteracting fermions in a rotating
optical lattice with a superimposed harmonic trapping potential. This method
also allows one to measure the quantized Hall conductance, a feature which appears when the Fermi energy lies in an energy gap of the lattice potential.
Finally, we explore the Bardeen-Cooper-Schrieffer type of pairing of fermionic
atoms in optical lattices under an artificial magnetic field by paying special
attention to single-particle degeneracies and present our results for the vortex
lattice structure of the paired fermionic superfluid phase.
Keywords
Ultracold atomsVortex lattice
Bardeen-Cooper-Schrieffer type of pairing
Topological Hofstadter insulator
P band
Bosonic fractional quantum Hall states
Superfluid-Mott insulator transition
Artificial magnetic field
Rotating optical lattices