The main theme of this thesis is the interplay between superuidity and localization,
in a system of strongly correlated Bose particles. Driving this investigation is the search
for yet unobserved phases of matter, such as the so-called supersolid. Using state-of-the-
art, numerically exact computer simulations, we have carried out an extensive theoretical
investigation of the effects of long-range interactions, inhomogeneity, disorder and frustration in a simple model of lattice Bosons. In particular, we explore the scenario of
vacancy- and interstitial-based supersolid phases of hard core bosons on a square lattice,
interacting repulsively via a nearest-neighbour and next-nearest neighbour potential. Secondly, in an attempt to model the physics of a layer of helium adsorbed on a corrugated
substrate, an additional superlattice of the absorption sites is imposed to the system of
hard core bosons, and the resulting low temperature phase diagram is studied. Finally,
the possibility of actually inducing by disorder superuidity (superglass) in a system that
does not display it in the absence of disorder is demonstrated. The quantitative and qual-
itative predictions at which we have arrived appear to be at least in principle testable
experimentally, for example by performing measurements on ultracold atoms in optical
lattices.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:AEU.10048/1167 |
| Date | 11 1900 |
| Creators | Dang, Long |
| Contributors | Massimo Boninsegni (Physics), Kevin Beach (Physics), Mauricio Sacchi (Physics), Craig Heinke, Physics), Alex Brown (Chemistry), Mona Berciu (Physics), University of British Columbia |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Thesis |
| Format | 2689026 bytes, application/pdf |
| Relation | http://prb.aps.org/abstract/PRB/v78/i13/e132512 (2008), http://prb.aps.org/abstract/PRB/v79/i21/e214529 (2009), http://arxiv.org/abs/1003.1367 (2010) |
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