Show simple item record

dc.contributor.advisorRiseborough, Peter
dc.creatorKANBUR, DERYA
dc.date.accessioned2020-11-04T16:09:47Z
dc.date.available2020-11-04T16:09:47Z
dc.date.issued2014
dc.identifier.other914186439
dc.identifier.urihttp://hdl.handle.net/20.500.12613/3083
dc.description.abstractIn this thesis, we have investigated the lowest-energy members of the quantized intrinsically localized modes of vibration (ILMs) of the monatomic ß Fermi-Pasta-Ulam Hamiltonian in three-dimensions. We analytically find the excitation of different center of mass momenta. Using the Ladder Approximation, we find that the ILMs occur preferentially for centre of mass momenta at which the van-Hove singularities in the two-phonon density of states coalesce. When the ILMs first form they split off from the top of the two-phonon continuum. The ILMs can be categorized as having a spin of either S=2 or S=0 and have other internal quantum numbers. Moreover, the S=0 ILMs form for lower values of the interaction than the S=2 ILMs. We also focus on the temperature dependence of the ILMs. At zero temperature, the ILMs can form in three-dimensions, but only if the interaction exceeds a minimum value. As the temperature is raised, the magnitude of the minimal interaction required to stabilize the ILM is reduced. This is in a qualitative agreement with the experiments of Manley {\it et al.}, which only found the ILMs of NaI at elevated temperatures. We have also examined the ILM many-body wave functions and find that the relative coordinate part of the wave functions has symmetries associated with internal quantum numbers. According to our numerical results, the localization length increases with decreasing values of the strength of interaction. The results are presented in D. Kanbur and P. S. Riseborough, Phil. Mag. Letts, 94, 424-432 (2014) and D. Kanbur and P. S. Riseborough, Phys. Rev. B, 90, 134301 (2014). This work was supported by the US Department of Energy, Office of Basic Energy Science, Materials Science and Engineering through the award DEFG02-84ER45872.
dc.format.extent170 pages
dc.language.isoeng
dc.publisherTemple University. Libraries
dc.relation.ispartofTheses and Dissertations
dc.rightsIN COPYRIGHT- This Rights Statement can be used for an Item that is in copyright. Using this statement implies that the organization making this Item available has determined that the Item is in copyright and either is the rights-holder, has obtained permission from the rights-holder(s) to make their Work(s) available, or makes the Item available under an exception or limitation to copyright (including Fair Use) that entitles it to make the Item available.
dc.rights.urihttp://rightsstatements.org/vocab/InC/1.0/
dc.subjectPhysics, Condensed Matter
dc.titleThe "Quantized Intrinsically Localized Modes" of A Three-Dimensional Lattice
dc.typeText
dc.type.genreThesis/Dissertation
dc.contributor.committeememberVarnum, Susan A.
dc.contributor.committeememberBurkhardt, T. W. (Theodore W.), 1940-
dc.contributor.committeememberMetz, Andreas
dc.contributor.committeememberWu, Xifan
dc.description.departmentPhysics
dc.relation.doihttp://dx.doi.org/10.34944/dspace/3065
dc.ada.noteFor Americans with Disabilities Act (ADA) accommodation, including help with reading this content, please contact scholarshare@temple.edu
dc.description.degreePh.D.
refterms.dateFOA2020-11-04T16:09:47Z


Files in this item

Thumbnail
Name:
TETDEDXKANBUR-temple-0225E-119 ...
Size:
5.244Mb
Format:
PDF

This item appears in the following Collection(s)

Show simple item record