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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Quasiparticle calculations for metal hydrides

Alford, John Ashley, II 12 1900 (has links)
No description available.
2

Quasiparticles in quantum spin chains with strong axial exchange anisotropy /

Lu, Ping, January 2009 (has links)
Thesis (Ph.D.) -- University of Rhode Island, 2009. / Typescript. Includes bibliographical references (leaves 132-135).
3

Some problems on the theory of many body systems

Paterson, Mary T. January 1968 (has links)
No description available.
4

Squeezing, entanglement and excitation spectra of BECs in optical lattices. / 光格子势中玻色爱因斯坦凝聚体的压缩,纠缠与激发谱 / Squeezing, entanglement and excitation spectra of BECs in optical lattices. / Guang ge zi shi zhong bo se ai yin si tan ning ju ti de ya suo, jiu chan yu ji fa pu

January 2007 (has links)
Liu, Xiaopi = 光格子势中玻色爱因斯坦凝聚体的压缩,纠缠与激发谱 / 刘小披. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2007. / Includes bibliographical references (leaves 97-100). / Abstracts in English and Chinese. / Liu, Xiaopi = Guang ge zi shi zhong bo se ai yin si tan ning ju ti de ya suo, jiu chan yu ji fa pu / Liu Xiaopi. / Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Review of Superfluidity and B.E. Condensation --- p.1 / Chapter 1.2 --- Our Understanding of superfluidity --- p.4 / Chapter 1.3 --- Non-classicality in Quantum Mechanics --- p.8 / Chapter 2 --- One-Component BECs in optical lattices --- p.16 / Chapter 2.1 --- Introduction: The Hamiltonian --- p.16 / Chapter 2.2 --- The Hamiltonian in Quasi-momentum space --- p.19 / Chapter 2.3 --- Bogoliubov Method and Equation of Motion --- p.21 / Chapter 2.3.1 --- Squeezing and Condensation --- p.27 / Chapter 2.3.2 --- Two-mode Entanglement and Squeezing --- p.31 / Chapter 3 --- Matrix method approach to ground state BECs --- p.39 / Chapter 3.1 --- Matrix method --- p.39 / Chapter 3.2 --- Ground state and Particle Distribution --- p.42 / Chapter 3.3 --- Correlation in Pair Ground State --- p.46 / Chapter 4 --- Attractive BECs in optical lattices --- p.50 / Chapter 5 --- 2-component BECs in optical lattice --- p.56 / Chapter 5.1 --- Model Hamiltonian --- p.56 / Chapter 5.2 --- Excitation Spectrum and Critical super-fluid velocity --- p.59 / Chapter 5.3 --- Excitation spectrum and Phase Separation Dynamics --- p.63 / Chapter 5.4 --- Excitation Spectrum for Asymmetric 2-component BECs --- p.67 / Chapter 6 --- Multi-Mode Squeezing of 2-component BECs in optical lattices --- p.69 / Chapter 6.1 --- Simultaneous Diagonalization --- p.69 / Chapter 6.2 --- Equation of Motion and Variance Matrix --- p.70 / Chapter 6.3 --- U(n) Squeezing of Variance Matrix --- p.75 / Chapter 6.4 --- Squeezing in the case qA≠ qB and nA≠ nB --- p.82 / Chapter 7 --- Entanglement between 2-component BECs in optical lattices --- p.83 / Chapter 7.1 --- Variance matrix in block diagonal --- p.83 / Chapter 7.2 --- 2-component entangled variance matrix --- p.86 / Chapter 7.3 --- Logarithmic negativity --- p.89 / Chapter 7.4 --- Beat oscillation mode of logarithmic negativity --- p.91 / Chapter 8 --- Conclusion and Outlook --- p.95 / Bibliography --- p.97
5

Interaction between collective coordinates and quasiparticles in spintronic devices

Núñez, Álvaro Sebastián 28 August 2008 (has links)
Not available / text
6

Studies of the vortex state in high-temperature superconductors

Knapp, Daniel. Kallin, Catherine. January 1900 (has links)
Thesis (Ph.D.)--McMaster University, 2006. / Supervisor: Catherine Kallin. Includes bibliographical references (p. 168-177).
7

Interaction between collective coordinates and quasiparticles in spintronic devices

Núñez, Álvaro Sebastián, January 1900 (has links) (PDF)
Thesis (Ph. D.)--University of Texas at Austin, 2006. / Vita. Includes bibliographical references.
8

Ultrafast lattice dynamics in excitonic self-trapping of quasi-one dimensional materials

Morrissey, Francis Xavier, January 2007 (has links) (PDF)
Thesis (Ph. D.)--Washington State University, May 2007. / Includes bibliographical references.
9

Termodinâmica de quase-partículas /

Gardim, Fernando Gonçalves. January 2009 (has links)
Orientador: Fernanda Monti Steffens / Banca: Sandra dos Santos Padula / Banca: Jun Takahashi / Banca: Eduardo Souza Fraga / Banca: Manuel Máximo Bastos Malheiro de Oliveira / Resumo: O problema da inconsistência termodinâmica do modelo de quase-partículas foi parcialmente resolvido por Gorenstein e Yang há quase duas décadas. Entretanto sua solução mostra-se como uma solução particular para o problema da inconsistência termodinâmica. Este trabalho apresenta a solução geral para o modelo de quase-partículas a partir da generalização da solução de Gorenstein-Yang, estudando-se assim o modelo de quase-partículas em dois cenários diferentes: para o caso onde este é formado apenas por bósons, e quando é formado por bósons mais férmions e anti-férmions. Para o caso bosônico assume-se os bósons não-massivos, em um sistema à temperatura finita e potencial químico nulo, obtendo então sua solução termodinâmica geral. A partir desta utiliza-se uma solução particular para descrever a matéria desconfinada, o Plasma de Glúons, e compara-se esta solução com os dados provenientes de QCD na rede para pressão, entropia e energia interna. Estuda-se também a solução geral para um sistema à temperatura e potencial químico finitos formado por férmions, anti-férmions e bósons. O limite assintótico destas soluções também é analisado. Uma solução particular, análoga à utilizada no caso apenas de bósons, é utilizada para descrever os resultados de QCD na rede, para um Plasma de Quarks e Glúons. Este formalismo permite descrever o Plasma de Quarks e Glúons em toda região de desconfinamento. Seja no caso bosônico, ou no caso de bósons e férmions, encontra-se uma solução mais simples que a de Gorenstein-Yang para descrever o QGP / Abstract: The thermodynamics quasi-particle problem was partially solved by Gorenstein and Yang. Nevertheless, its solution is a particular solution of the thermodynamic inconsistency problem. In this work the thermodynamics of the quasi-particle model is studied from a generalization of the Gorenstein-Yang solution. This work is split in two parts: For the case of finite temperature and vanishing chemical potential for non-massive bosons, and for finite temperature and Chemical potential of anti-fermions, fermions plus bosons. For the boson case is computed the thermodynamical general solution and from it, a particular solution it is used to describe the deconfined matter, Gluon Plasma. This solution is compared to QCD lattice data, thus the pressure, entropy and internal energy can be fitted. Also is developed the solution for a system composed by fermions, antifermions and gluons. An analogue solution to boson case it is used to describe the real case, the Quark Gluon Plasma. It is shown that solution is able to describe the lattice data. This general formalism allows study the QGP in all deconfined region. Whether in the bosonic case, or in bosonic plus fermionic case, it is found a simpler solution than the Gorenstein-Yang / Doutor
10

Visualizing Quasiparticle Scattering of Nematicity in NaFeAs and of Topological Surface States in MoTe2

Andrade, Erick Fernando January 2018 (has links)
Scanning tunneling microscopy has been a powerful tool in expanding our understanding in the study of condensed matter physics. Many of the exotic materials of interest exhibit rich phases of matter at different temperatures and pressures. In order to probe the rich array of phases we developed a novel technique of combining scanning tunneling microscopy with tunable temperature and tunable mechanical strain in ultra high vacuum conditions. The mechanisms that give rise to high temperature superconductivity has been a long standing problem in physics. The discovered of iron-based high temperature superconductors (pnictides) have spurred much research into the mechanisms that give rise to the different exotic states observed in these new materials in hopes to better understand the underlying nature of unconventional superconductivity. Here we present a detailed study of the Nematic ordered phase in the prototypical iron- based high temperature superconductor, NaFeAs. Using our novel strain, temperature, scanning tunneling microscopy technique, we can attain an atomic-resolution view of the effects of the nematic phase on the local density of states along with the effects of anisotropic strain on the electronic structure. We further systematically study NaFeAs along both axes of the phase diagram, tuning temperature and Cu doping. We probe the material from the parent compound to beyond the supercon- ducting dome with increased Cu doping and from superconducting temperatures towell above the structural transition temperatures. Using our novel strain, temperature, scanning tunneling microscopy technique we nanoscopically identified the region of long-range nematic order and the region of nematic fluctuations in the phase diagram and find that true long range nematic order sets in at the tetragonal to orthorhombic structural transition temperature but nematic fluctuations continue at higher temperatures and also into the overdoped regime, then seemingly disappearing at the edge of the superconducting dome. We further find that our applied stain increasing the amplitude of the nematic fluctuations showing strong nonlinear coupling between strain and electronic nematicity. The power of our novel strain, temperature, scanning tunneling microscopy tech- nique in probing quasiparticle interference proves ideal for studying the topological, Weyl semimetal 1T’-MoTe 2 . In it’s orthorombic phase the material has topologically nontrivial protected surface Fermi arcs. By measuring quasiparticle interference in this material at different temperatures we can probe both topologically nontrivial phase (orthorhombic phase) and the topologically trivial phase (monoclinic phase). In the topologically nontrivial phase we see quasiparticle interference measurements in good agreement with angular resolved photoemission spectroscopy and theoretical calculations. In the topologically trivial phase we see the lack of the quasiparticle interference coming from the trivial surface state.

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