Physics Commons^™

Physical Properties Of Unconventional Superconductors, Valentina Anatolyevna Kuznetsova

Doctoral Dissertations

In the following development, we attempt to obtain basic physical properties of majority of unconventional superconductors through a Bardeen-Cooper-Schrieffer-type weak-coupling approach. The method we adopted in our study is model-independent. The weak-coupling approach depends only on the symmetry of the coupling, not on its origin. It is known that a general analysis of physical properties of unconventional superconductors is possible, but has not been done yet. The goal of our work is to develop and test such analysis, using available experimental data.

Since paramagnetic limiting for spin-singlet superconductors can be suppressed in superconductors with broken inversion symmetry of crystal lattice, …

Static And Dynamic Magnetism In The Electron-Doped High-Temperature Superconductor Pr0.88Lace0.12Cuo4-Δ And In The F-Electron, Non-Fermi Liquid Alloy Sc1-XUXPd3, Stephen Dennis Wilson

Doctoral Dissertations

Here we present detailed studies of the spin dynamics within the electron-doped high temperature superconductor Pr_.88LaCe_.12CuO_4-δ (PLCCO) and within the non-Fermi liquid metal Sc_1-xU_xPd₃ (ScUPd). Comprehensive neutron scattering experiments were carried out mapping the evolution of magnetism within these systems as they are tuned across their respective phase diagrams. The novel features of the magnetic spectra within these systems are correlated with known anomalies in their quasiparticle behaviors driven through either the appearance of a superconducting phase in PLCCO or the emergence of a non-Fermi liquid phase in ScUPd.

For …

Structure And Transport Properties Of Epitaxial Oxide Thin Films: From Synthesis To Characterization, Junsoo Shin

Doctoral Dissertations

Epitaxial thin films and heterostructures based on perovskite oxides have attracted significant attention in physics since perovskites exhibit an enormous range of electrical, magnetic, and optical properties, making them exciting systems for studies of the fundamental physical mechanisms of interactions between electron, lattice, and spin degrees of freedom. This dissertation has been focused on ferroelectricity in lowdimensional ferroelectric materials using ultra-thin ferroelectric epitaxial films (BaTiO₃) with a metallic electrode (SrRuO₃) by studying polarized ordering of the crystal structure and electronic transport through the films. High quality and highly oxidized epitaxial films are a prerequisite for the …

Surface Plasmon Enhanced Heating Of Gold Nanoparticles: A Plasmonic Optical Switch, Philip Gareth Evans

Doctoral Dissertations

Recent work by Lereu et al. (Appl. Phys. Lett. Vol. 86, 154101, 2005) demonstrates a method of all-optical transfer of modulation signals using surface plasmon excitation on thin gold films. Localized heating of the film, resulting from surface plasmon decay, alter the optical properties of the device. A similar optical modulation method is now presented using gold nanoparticles. Computational models are used to generate realistic values of the thermo-optical response of gold and the thermal dynamics of a hot nanoparticle-substrate device. Differential pump-probe reflectivity measurements were perferomed and demonstrate modulation frequencies of upto 10kHz, an improvement of two orders of …