Condensed Matter Physics Commons^™

Transient Transmission Oscillations In Doped And Undoped Lithium Niobate Induced By Near-Infrared Femtosecond Pulses, Bryan J. Crossman, Gregory J. Taft

Physics Faculty Publications

Transient transmission oscillations in X-cut and Z-cut congruent, iron-doped, and magnesium-doped lithium niobate samples were measured using 50 fs, 800 nm, 0.5 nJ pulses from a self-mode-locked Ti:sapphire laser in an optical pump–probe system. Several Raman-active oscillation modes excited by these pulses were observed as changes in the transmitted probe intensity versus time delay between the pump and probe pulses. The samples were rotated to determine how the incident polarization of the pump pulses affects the mode excitations. The observed Raman-active oscillations correspond to previously reported symmetry modes measured with traditional, continuous-wave, Raman spectroscopy using the same scattering …

Boundary Twists, Instabilities, And Creation Of Skyrmions And Antiskyrmions, Aldo Raeliarijaona, Rabindra Nepal, Alexey Kovalev

Department of Physics and Astronomy: Faculty Publications

We formulate and study the general boundary conditions dictating the magnetization profile in the vicinity of an interface between magnets with dissimilar properties. Boundary twists in the vicinity of an edge due to Dzyaloshinskii-Moriya interactions have been first discussed by Wilson et al. [Phys. Rev. B 88, 214420 (2013)] and by Rohart and Thiaville [Phys. Rev. B 88, 184422 (2013)]. We show that in general case the boundary conditions lead to the magnetization profile corresponding to the Néel, Bloch, or intermediate twist. We explore how such twists can be utilized for creation of skyrmions and antiskyrmions, e.g., in a view …

Computational Prediction, Characterization, And Methodology Development For Two-Dimensional Nanostructures: Phosphorene And Phosphide Binary Compounds., Congyan Zhang

Electronic Theses and Dissertations

In this thesis, a comprehensive computational simulation was carried out for predicting, characterizing, and applications of two-dimensional (2D) materials. The newly discovered GaP and InP layers were selected as an example to demonstrate how to explore new 2D materials using computational simulations. The performance of phosphorene as the anode material of Lithium-ion battery was discussed as the example of the application of 2D material. Furthermore, the semi-empirical Hamiltonian for phosphorous and lithium elements have been developed for our future work on the application of phosphorus and lithium-based systems. The novel 2D materials of GaP and InP binary compounds were found …

Directly Photoexcited Dirac And Weyl Fermions In Zrsis And Nbas, Christopher P. Weber, Leslie M. Schoop, Stuart S. P. Parkin, Robert C. Newby, Alex Nateprov, Bettina Lotsch, Bala Murali Krishna Mariserla, J. Matthew Kim, Keshav M. Dani, Hans A. Bechtel, Ernerst Arushanov, Mazhar Ali

Physics

We report ultrafast optical measurements of the Dirac line-node semimetal ZrSiS and the Weyl semimetal NbAs, using mid-infrared pump photons from 86 meV to 500 meV to directly excite Dirac and Weyl fermions within the linearly dispersing bands. In NbAs, the photoexcited Weyl fermions initially form a non-thermal distribution, signified by a brief spike in the differential reflectivity whose sign is controlled by the relative energy of the pump and probe photons. In ZrSiS, electron-electron scattering rapidly thermalizes the electrons, and the spike is not observed. Subsequently, hot carriers in both materials cool within a few picoseconds. This cooling, as …

Physical Electronic Properties Of Self-Assembled 2d And 3d Surface Mounted Metal-Organic Frameworks, Radwan Elzein

USF Tampa Graduate Theses and Dissertations

Metal-organic frameworks stand at the frontiers of molecular electronic research because they combine desirable physical properties of organic and inorganic components. They are crystalline porous solids constructed by inorganic nodes coordinated to organic ligands to form 1D, 2D, or 3D structures. They possess unique characteristics such as ultrahigh surface area crystal lattices up to 10000 m² g^-1, and tunable nanoporous sizes ranging from 0.2 to 50 nm. Their unprecedented structural diversity and flexibility beyond solid state materials can lead to unique properties such as tailorable electronic and ionic conductivity which can serve as interesting platforms for a …

The Effects Of Pressure And Magnetic Field On Phase Transitions And Related Physical Properties In Solid State Caloric Materials, Ahmad Ikhwan Us Saleheen

LSU Doctoral Dissertations

Solid-state caloric effects, such as the magnetocaloric (MCE) and barocaloric (BCE) effects, may be utilized in future cooling technologies that are more efficient and environment-friendly. Large caloric effects often occur near phase transitions, especially near coupled first-order magnetostructural transitions (MST), and are initiated by external parameters, such as magnetic field or hydrostatic pressure. In this dissertation, the effects of pressure, temperature, and magnetic field on the phase transitions in three material systems are studied in order to elucidate how the respective caloric effects are affected.

In the first study, the realization of a coupled MST in a MnNiSi-based system through …

Genetic Algorithm Design Of Photonic Crystals For Energy-Efficient Ultrafast Laser Transmitters, Troy A. Hutchins-Delgado

Shared Knowledge Conference

Photonic crystals allow light to be controlled and manipulated such that novel photonic devices can be created. We are interested in using photonic crystals to increase the energy efficiency of our semiconductor whistle-geometry ring lasers. A photonic crystal will enable us to reduce the ring size, while maintaining confinement, thereby reducing its operating power. Photonic crystals can also exhibit slow light that will increase the interaction with the material. This will increase the gain, and therefore, lower the threshold for lasing to occur. Designing a photonic crystal for a particular application can be a challenge due to its number of …

Two-Dimensional Layered Materials (Graphene-Mos2) Nanocatalysts For Hydrogen Production, Jacob Dobler, Taylor Robinson, Sanju Gupta 7455940

Posters-at-the-Capitol

Recent development of two-dimensional layered materials including graphene-family and related nanomaterials have arisen as potential game changer for energy, water and sensing applications. While graphene is a form of carbon arranged hexagonally within atomic thin sheet, MoS₂ is becoming a popular, efficient, and cost-effective catalyst for electrochemical energy devices, in contrast to expensive platinum and palladium catalysts. In this work, we electrochemically desulfurize few-layer molybdenum disulfide (MoS₂) and aerogels with reduced graphene oxide (rGO) prepared under hydrothermal conditions ((P< 20 bar, T< 200 ^oC), for improving hydrogen evolution reaction (HER) activity via point defects (S-vacancy). Moreover, the interactions between rGO …

Physical Properties Of Engineered Nanocomposites For Defense Applications, Alex Henson, Sanju Gupta

Posters-at-the-Capitol

Polymer nanocomposites are significant for modern and future technologies (aerospace, defense, water purification etc.) due to their tailored properties, lightweight and low cost. However, ‘forward’ engineered polymer (host matrix) composites with smaller size nanoparticles (guest) providing desired properties targeting specific applications remains a challenging task as they depend largely on nanoparticles size, shape and loading (volume fraction). This study develops polymer nanocomposites impregnated with ‘organic-inorganic’ silsesquioxane nanoparticles and graphene nanoribbons, and investigates microscopic structure and dynamics of interfacial layer to predict macroscale properties. The nanocomposites consist of poly(2-vinylpyridine) (P2VP) polymer (segment ~5nm) with spherical silsesquioxane nanoparticles (diameter ~2-5nm) and planar …

Rectifying Garbage-In Equals Garbage-Out Using A Secondary Electron Yield Materials Database, Phil Lundgreen, Jr Dennison

Presentations

No abstract provided.

An Introduction To Quantile-Quantile Plots For The Experimental Physicist, Allen Andersen, Jr Dennison

Journal Articles

No abstract provided.

Non-Abelian Quasiholes In Lattice Moore-Read States And Parent Hamiltonians, Sourav Manna, Julia Wildeboer, Germán Sierra, Anne E. B. Nielsen

Physics and Astronomy Faculty Publications

This work concerns Ising quasiholes in Moore-Read type lattice wave functions derived from conformal field theory. We commence with constructing Moore-Read type lattice states and then add quasiholes to them. By use of Metropolis Monte Carlo simulations, we analyze the features of the quasiholes, such as their size, shape, charge, and braiding properties. The braiding properties, which turn out to be the same as in the continuum Moore-Read state, demonstrate the topological attributes of the Moore-Read lattice states in a direct way. We also derive parent Hamiltonians for which the states with quasiholes included are ground states. One advantage of …

An Analysis Of Variations In Published Secondary Electron Yield Measurements Of Copper, Phil Lundgreen, Jr Dennison

Posters

No abstract provided.

Optical Transmission Of Irradiated Optical Filters, Jr Dennison, Ashlan Keeler, Brian Wood, Jonh Mojica Decena

Presentations

No abstract provided.

Characterization Of Electron Yield Suppression With Carbon Nanotube Forest Grown On Silicon Substrates, Brian Wood, Jordan Lee, Justin Christensen, Gregory Wilson, Jr Dennison, T. -C. Shen

Presentations

No abstract provided.

Simulating Microgravity And Space Radiation With A Rotary Cell Culture System (Rccs), Alexandra Nelson, Lori Caldwell, Eryn Hanson, Jr Dennison, Elizabeth Vargis

Presentations

No abstract provided.

Characterization Of Electron Yield Suppression With Carbon Nanotube Forest Grown On Silicon Substrates, Brian Wood, Jordan Lee, Gregory Wilson, Jr Dennison, T. -C. Shen

Presentations

No abstract provided.

Real-Time Video Processing Of Arcing Events To Determine Coincidence, Jr Dennison, Gregory Wilson, Jonh Mojica Decena, Brian Wood

Posters

No abstract provided.

Electron Yield Measurements Of Multilayer Conductive Materials, Gregory Wilson, Matthew Robertson, Jordan Lee, Jr Dennison

Presentations

No abstract provided.

Electron Yield Measurements Of Multilayer Conductive Materials, Gregory Wilson, Matthew Robertson, Jordan Lee, Jr Dennison

Presentations

No abstract provided.

Detection And Classification Of High Energy Beta Radiation Induced Damage Of Raspberry Pi Zero Intended For Opal Cubesat, Jonh Mojica Decena, Jr Dennison, Brian Wood, Ryan J. Martineau, Michael Taylor

Presentations

No abstract provided.

Simulating Microgravity And Space Radiation With A Rotary Cell Culture System (Rccs), Alexandra Nelson, Lori Caldwell, Eryn Hanson, Jr Dennison, Elizabeth Vargis

Presentations

No abstract provided.

Real-Time Video Processing Of Arcing Events To Determine Coincidence, Jr Dennison, Gregory Wilson, Jonh Mojica Decena, Brian Wood

Presentations

No abstract provided.

Charging Effects Of High Voltage Probe Pulse On Pulsed Electroacoustic Measurements, Zachary Gibson, Jr Dennison, Lee Pearson, Erick Griffiths, Anthony Pearson

Presentations

No abstract provided.

Charging Effects Of High Voltage Probe Pulse On Pulsed Electroacoustic Measurements, Zachary Gibson, Jr Dennison, Erick W. Griffiths, Lee Pearson, Anthony Pearson

Presentations

No abstract provided.

Characterizing Vibrationally Induced Damage Of Carbon Nanotube Forests, Jordan Lee, Brian Wood, Ashlan Keeler, Jr Dennison, T. -C. Shen

Presentations

No abstract provided.

Electron Yield Of A Carbon-Composite Nanodielectric, Jr Dennison, Matthew Robertson, Gregory Wilson, Justin Christensen

Presentations

No abstract provided.

Detection And Classification Of High Energy Beta Radiation Induced Damage Of Raspberry Pi Zero Intended For Opal Cubesat, Jonh Mojica Decena, Ryan J. Martineau, Jr Dennison, Brian Wood, Michael J. Taylor

Presentations

No abstract provided.

Electron Yield Of Carbon-Composite Nanodielectric, Matthew Robertson, Justin Christensen, Gregory Wilson, Jr Dennison

Presentations

No abstract provided.

Optical Transmission Of Irradiated Optical Filters, Ashlan Keeler, Jr Dennison, Brian Wood, Jonh Mojica Decena

Presentations

No abstract provided.