Condensed Matter Physics Commons^™

How Graphene’S Berry Dipole Is Determined By Its Atomic Registry With A Substrate, Hannah K. Isbell

Physics Undergraduate Honors Theses

Since graphene’s discovery in 2004, it has been established as one of the most important materials in recent condensed matter history. Understanding its properties and potential uses has been the subject of intense scientific research around the world. Graphene’s unique physical properties allow it to serve a wide variety of purposes, from its everyday role in the formation of graphite in pencils to its more cutting-edge scientific functions in electronics and energy storage. Gaining a better understanding of graphene’s rich quantum landscape through geometric and topological phenomena, like Berry curvature and Berry dipole, could have significant implications for both theoretical …

Charge And Spin Transport In Nanowires With Spin-Orbit Coupling, Ryan Perrin

All Dissertations

Nanowires exhibiting Fermi-level pinning have strong radial electron confinement and thus can be modeled as a two-dimensional electron gas wrapped around the core. In III-V semiconductor structures, two forms of spin-orbit coupling are generated by breaking inversion symmetries in the crystal (Dresselhaus) and the overall structure of the nanowires (Rashba). The first goal of this thesis is to understand the single-particle energy spectrum in nanowires with variable cross sections and the quantum oscillations that can be driven in them by the application of a magnetic field parallel to the axis of the wire. To this end, the eigenfunctions and eigenvalues …

Young Professionals, Zachary Gibson

Journal Articles

Like many of us, I have attended numerous panels, seminars, and workshops geared toward helping young professionals and students. The more senior professionals are gathered for us to question and tap them for wisdom and anecdotes. One such question that inevitably comes up in one form or another is, “How did you get to where you are?” A thinly veiled question intending to ask how can one get to the same or similar position. The response often begins with a soft chuckle and a “well … ” Their answers are caveated by “my path was not the typical path.”

An Open-Framework Iron-Selenite As Cathode For Li- Ion Batteries, Sutapa Bhattacharya, Aleksandr V. Chernatynskiy, Amitava Choudhury

Miners Solving for Tomorrow Research Conference

No abstract provided.

Understanding Microsoft's Qubit, Alexander Escobedo, Eric Deyo

SACAD: Scholarly Activities

In this presentation, we attempt to understand the device that was recently developed by the Microsoft Azure Quantum group that creates, manipulates, and measures qubits using Majorana Zero Modes (MZM).

Spectral Width Of Maximum Deposition Eigenchannels In Diffusive Media, Rohin E. Mcintosh, Arthur Goetschy, Nicholas Bender, Alexey Yamilov, Chia Wei Hsu, Hasan Yllmaz, Hui Cao

Physics Faculty Research & Creative Works

The maximum deposition eigenchannel provides the largest possible power delivery to a target region inside a diffusive medium by optimizing the incident wavefront of a monochromatic beam. It originates from constructive interference of scattered waves, which is frequency sensitive. We investigate the spectral width of the maximum deposition eigenchannels over a range of target depths using numerical simulations of a 2D diffusive system. Compared to tight focusing into the system, power deposition to an extended region is more sensitive to frequency detuning. The spectral width of enhanced delivery to a large target displays a rather weak, nonmonotonic variation with target …

Enhanced Vapour Detection Through Electrospun Metal-Oxide Nanofibers, Sri Varshini K Ms

Theses and Dissertations

The objective of this work is to fabricate metal oxide-based nanofibers, which helps in monitoring indoor air quality, which is deteriorating due to VOCs like Formaldehyde, Toluene, and Ammonia, commonly found in paints, plywood, and adhesives. Prolonged exposure to these VOCs can affect the respiratory and nervous system. They are classified as carcinogens by the IARC.

Based on the analysis, this work was framed to deposit Fe2O3, NiO, and ZnO/Fe2O3 as well ZnO/NiO and Fe2O3/NiO nanofibers on the glass substrate through horizontal electrospinning method. The obtained nanofibers are vacuum annealed at 50 ℃ for 30 mins to remove the water …

Effect Of Niobium Dopant On Zno Thin Films Prepared Via The Sol–Gel Spin Coating Method, Kevin Alvin Eswar, Nur Fairuz Rostan, Maryam Mohamad, Rabiatuladawiyah Md Akhir, Rosfayanti Rasmidi, Muliyadi Guliling, Najwa Ezira Azhar, Irmaizatussyehdany Buniyamin, Mohd Firdaus Malek, Mohamad Rusop Mahmood, Husairi Fadzilah Suhaimi, Saifollah Abdullah

Makara Journal of Science

Thin films of zinc oxide (ZnO) and niobium (Nb)-doped ZnO were deposited on a glass substrate using the sol–gel spin coating method. Diethanolamine, isopropyl alcohol, and zinc acetate served as the stabilizers, solvent, and starting ma-terial, respectively. Niobium pentachloride was employed as the dopant source. Energy-dispersive X-ray analysis con-firmed Nb incorporation. Field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), and ultravio-let–visible spectroscopy (UV–Vis) analyses characterized the morphology, structure, and optics of the films, respective-ly. Both films, comprising nanoparticles, were visible in FESEM. Nb doping reduced the particle size from 44.2 nm to 35.8 nm. The XRD peaks at 31.23°, …

Quantum Control And Simulation Using Hamiltonian Engineering In Solid-State Nmr, Linta Joseph

Dartmouth College Ph.D Dissertations

Lattices of dipolar coupled nuclear spins in natural crystals are large, interacting quantum systems -- ideal platforms to simulate non-equilibrium many-body dynamics. Using the magnetic resonance toolkit, which includes Dynamic Nuclear Polarization (DNP), Hamiltonian engineering, and multiple-quantum Nuclear Magnetic Resonance (NMR) experiments, we study aspects of coherent control, manipulation, and readout of the complex dynamics of the spin system in NMR quantum simulation.

First, applying Hamiltonian engineering sequences, we control the system evolution. Specifically, we use a combination of numerical simulations and NMR experiments on adamantane to evaluate and compare the performance of several known sequences that aim to suppress …

Silver-Alloyed Cigs Thin-Film Solar Cells On Flexible Stainless-Steel Substrate, Zhi Huang

Dissertations, Theses, and Capstone Projects

Our dissertation demonstrates the optimization of ACIGS (Ag-Cu-In-Ga-Se) thin-film solar cells, achieving an efficiency of 20.4% through the combined effects of silver incorporation and alkali metal post-deposition treatment (PDT). The incorporation of 2.8% Ag into the CIGS lattice enhanced crystal quality, reduced disorder, and widened the bandgap by 0.103 eV, as evidenced by a significant reduction in Urbach energy. These improvements resulted in stronger light absorption, increased carrier generation, and enhanced photovoltaic parameters, including a short-circuit current density Jsc of 35.31 mA/cm², an open-circuit voltage Voc of 0.74 V, and a fill factor (FF) of 75.8%. PDT using rubidium fluoride …

Anderson Transition For Light In A Three-Dimensional Random Medium, Alexey Yamilov, Hui Cao, Sergey E. Skipetrov

Physics Faculty Research & Creative Works

We study Anderson transition for light in three dimensions by performing large-scale simulations of electromagnetic wave transport in disordered ensembles of perfect-electric-conducting spatially overlapping spheres. A mobility edge that separates diffusive transport and Anderson localization is identified, revealing a sharp transition from diffusion to localization for light. Critical behavior in the vicinity of the mobility edge is well described by a single parameter scaling law. The critical exponent is found to be consistent with the value known for the Anderson transition of the orthogonal universality class. Statistical distribution of total transmission at the mobility edge is described without any fit …

Fabrication Of Microscale Oxide Architectures On Silicon Via A Cmos-Compatible, Deposition-Last Process, Jamal A. Brown

Material Science and Engineering Theses - Archive

This work explores the feasibility of integrating complex oxide devices on silicon using a CMOS-compatible, deposition-last approach. While previous demonstrations of this method have succeeded at larger scales, this study focuses on extending the process to microscale features, with lateral dimensions as small as two microns. The fabrication sequence begins with photolithographic patterning and reactive ion etching of the silicon substrate, followed by the deposition of a silicon nitride mask to delineate device regions. We then epitaxially grew SrTiO3 and La-doped SrTiO3 layers on top of the nitride mask via molecular beam epitaxy. Electrical transport measurements of the La:STO layer …

Beyond The Phonon Gas Model (Pgm): Unraveling The Unique Mechanistic Processes Dictating Thermal Transport In Highly Anharmonic And Disordered Materials, Sandip Thakur

Open Access Dissertations

Thermal transport in nonmetallic solids has traditionally been described by the phonon gas model (PGM), in which heat is carried by weakly interacting phonon quasiparticles in an ordered crystalline lattice. However, this model breaks down in materials characterized by strong anharmonicity, dynamic disorder, or structural complexity, features prevalent in many next-generation materials used in energy conversion, optoelectronics, and thermal management. This dissertation investigates thermal transport in such complex materials, including metal halide perovskites (MHPs), covalent organic frameworks (COFs), metal organic frameworks (MOFs), and 2D-3D heterostructures, through large-scale molecular dynamics (MD) simulations and frequency-resolved spectral analyses.

In MHPs, the work reveals …

A Random Walk Simulation Of Positron Annihilation Depth As A Function Of Positron Beam Energy, Saniya Anjum Aqeel Ahmed Yadgeer

Physics Theses - Archive

Depth resolved defect and chemical characterization studies using positron annihilation spectroscopy depend on the ability to estimate the fraction of positrons annihilating at surface, in the bulk, at defects or as Positronium. The depth resolution is limited by the implantation profile of the energetic positrons and the diffusion of the thermalized positrons. Here we implement a random walk simulation as described in S. Eichler et al. [1] to track the monoenergetic positrons implanted into multilayer graphene on Cu. For our simulations the implantation depths were sampled from a Makhovian distribution that has been shown to accurately represent the implantation profile …

A Fault-Tolerant Exchange-Coupled Spin-Ensemble Qubit At Elevated-Temperatures, Aniruddha Chakraborty

Theses and Dissertations

This thesis introduces a novel qubit architecture: the ferromagnetic exchange-coupled spin ensemble qubit (E-qubit), designed to address the noise-induced instability. In this work, the time evolution of the ensemble’s density matrix is studied using the Liouville–von Neumann equation. To benchmark against a single-spin qubit, the gate fidelity of an E-qubit is computed in the presence of thermal noise. Coherence time is also analyzed under identical thermal condition and a linear scaling is observed with qubit size . The results show that, at 6 K , the gate fidelity error (0.7 % ) of the seven- spin ensemble is an order …

Synthesis And Characterization Of Doped Rare-Earth Zinc Alloys, Partha Das

Graduate Theses/Dissertations

Rare-Earth-Zinc (RE-Zn) alloys doped with manganese represent a promising class of materials with diverse applications in magnetic, electronic, and thermoelectric devices. These alloys hold significant potential owing to the unique combination of rare-earth elements' properties with the versatility of zinc, augmented by manganese doping. In this study, I present the successful synthesis of ErMn_0.2Zn_11.8 alloys, achieved through self-flux method. The synthesized crystals were characterized using electron dispersive spectroscopy (EDS) and single crystal X-ray diffraction (XRD). Additionally, magnetic measurements were performed to investigate the magnetic properties. Future plans include DFT calculations and comparison study between Rare-Earth-Zinc alloys with …

Investigating The Roles Of Intrinsic Point Defects And Transition Metal Doping In Monolayer And Bulk Tis2, Patrick J. Keeney

UNF Graduate Theses and Dissertations

Within this thesis, the magnetic and electronic properties of various 1T-TiS₂ systems are thoroughly examined using density functional theory (DFT) and scanning tunneling microscopy (STM). Formation energies and electronic implications of intrinsic point defects in bulk TiS₂ and monolayer TiS₂ are analyzed by approximating a computational monolayer of TiS₂ as the surface layer of a bulk sample. This approximation is validated given that intralayer covalent bonding dominates interlayer van der Waals interactions. We conclude that the most energetically favorable intrinsic defects are Ti atoms settling above the outermost S plane and S vacancies. In addition, the …

Frustrated Quantum Magnetism: The Interplay Of Isotropic And Anisotropic Interactions With Application To Α-Rucl3, Evan M. Wilson

UNF Graduate Theses and Dissertations

We investigate how anisotropic spin interactions, including Dzyaloshinskii–Moriya and Kitaev terms, manifest across quantum spin systems ranging from a single S = 1/2 dimer to molecular spin clusters and layered magnetic materials. Beginning with an exact analysis of the spin dimer, we demonstrate how singlet–triplet mixing induced by Dzyaloshinskii–Moriya interaction directly influences both thermodynamic observables and inelastic neutron scattering spectra. These microscopic fingerprints are then extended to trimer, tetramer, and tetrahedron geometries, where field-induced phase transitions and heat capacity anomalies reveal the interplay between isotropic Heisenberg and anisotropic Kitaev exchanges. In the frustrated zigzag honeycomb lattice, we show that a …

Niobium Titanium Nitride Thin Film Deposition, Optimization, And Characterization, Hudson Horne

UNF Graduate Theses and Dissertations

Superconducting thin film devices such as Josephson junctions are a staple of cutting-edge quantum and classical computing architectures. Functional devices require optimized materials with properties suited to the device application; properties like superconducting critical temperature, critical current density, resistivity, and surface roughness are important depending on the intended device application. Niobium titanium nitride (NbTiN), a fcc transition metal nitride, is a promising material for these applications, with a superconducting critical temperature among the highest of the superconductors described by Bardeen, Cooper, and Schreiffer (BCS) theory. NbTiN has excellent mechanical and electrical characteristics and is easily deposited via reactive magnetron sputtering …

Theoretical Study Of Phase-Ordering Kinetics With An Anisotropic Surface Tension, Arjun Anand, Ben Vollmayr-Lee

Honors Theses

Coarsening describes the phase-separation dynamics that follows after a temperature quench from a stable to unstable region of the phase diagram in binary systems. Whereas binary systems with an isotropic surface tension have been thoroughly examined and modeled, the case of an anisotropic surface tension lacks the same degree of analysis and development. In this thesis, we demonstrate the self-consistency of the scaling hypothesis with an anisotropic surface tension in the dilute limit. We begin by assuming weak anisotropy in the surface tension and working only to first order in perturbation theory. Following a similar approach laid out in the …