Condensed Matter Physics Commons^™

Driven Dipolaritons In Van Der Waals Transition Metal Dichalcogenide Heterostructures: Properties And Applications, Patrick Serafin

Dissertations, Theses, and Capstone Projects

The need for advances in optical computation leads us toward the investigation of novel methods of re-routing light in optical circuits. The behavior and properties of electrically driven exciton-dipolaritons in van der Waals transition metal dichalcogenides are investigated as a platform for realizing working elements of a polaritronic transistor. In this work, we consider exciton-dipolaritons, which are three-way superposition of cavity photons, direct excitons, and indirect excitons in a bilayer semiconducting system embedded in an optical microcavity. We start by providing motivation for our study of polaritons and then survey the fundamental properties of exciton-dipolaritons. We also survey the basic …

Control Of Nonlinear Properties Of Van Der Waals Materials, Rezlind Bushati

Dissertations, Theses, and Capstone Projects

Van der Waals materials are a broad class of materials that exhibit unique optoelectronic properties. They provide a rich playground for which they can be integrated into current on-chip devices due to their nanometer-scale size, and be utilized for studying fundamental physics. Strong coupling of emitters to microcavities provides many opportunities for new exotic physics through the formation of hybrid quasi-particles exciton-polaritons. This thesis
focuses on exploring and enhancing nonlinearity of van der Waals materials through strongly coupling to microcavities. By taking advantage of the stacking order of TMDs, we show intense second-harmonic generation from bulk, centrosymmetric TMD systems. In …

Stability Of Two-Dimensional Magnetic Skyrmions, Amel Derras-Chouk

Dissertations, Theses, and Capstone Projects

Magnetic skyrmions are whirls formed by magnetic moments in a crystal. They have attracted attention largely due to their topological protection, which provides an avenue for technology like next-generation memory storage. The idea of topologically protected solutions of a quantum field theory was originally proposed by Tony Skyrme when he developed a model to explain the stability of hadrons in particle physics. His work has extended far beyond his original intent to several areas of condensed matter physics. Here we focus on skyrmions in magnetic materials.

Skyrme's original theory modeled excitations which exist in three spatial dimensions, a requirement for …

Electron Transport In Quantum Systems With Interaction, Sara Abedi

Dissertations, Theses, and Capstone Projects

No abstract provided.

Engineering Rare-Earth Based Color Centers In Wide Bandgap Semiconductors For Quantum And Nanoscale Applications, Gabriel I. López-Morales

Dissertations, Theses, and Capstone Projects

For many years, atomic point-defects have been readily used to tune the bulk properties of solid-state crystalline materials, for instance, through the inclusion of elemental impurities (doping) during growth, or post-processing treatments such as ion bombardment or high-energy irradiation. Such atomic point-defects introduce local ‘incompatible’ chemical interactions with the periodic atomic arrangement that makes up the crystal, resulting for example in localized electronic states due to dangling bonds or excess of electrons. When present in sufficient concentrations, the defects interact collectively to alter the overall bulk properties of the host material. In the low concentration limit, however, point-defects can serve …

Optical Studies Of Wide Bandgap Photonic Materials, Nikesh Maharjan

Dissertations, Theses, and Capstone Projects

In this dissertation work, optical properties of wide bandgap materials such as hexagonal Boron Nitride (h-BN) and Zinc Oxide (ZnO) have been studied. Deep UV photoluminescence spectroscopy was employed to study the optical properties of bulk h-BN and powder crystals using a laser of wavelength 200 nm, which is the fourth harmonic of Ti:Sapphire laser as excitation source. The properties and chemical compositions of annealed and unannealed bulk h-BN were investigated. The PL spectra from h-BN samples annealed at 900 ºC in ambient air, had strong phonon assisted band edge emissions along with a sharp atomic-like emission line at 4.09 …

Phase Transitions, Critical Phenomena, And Correlation Functions In The 2d Ising Model And Its Applications To Quantum Dynamics: A Tensor Network Approach, Sankhya Basu

Dissertations, Theses, and Capstone Projects

This thesis explores several aspects of the 2D Ising Model at both real and complex temperatures utilizing tensor network algorithms. We briefly discuss the importance of tensor networks in the context of forming efficient representations of wavefunctions and partition functions for quantum and classical many-body systems respectively, followed by a brief review of the tensor network renormalization algorithms to compute the one point and two point correlation functions. We use the Tensor Renormalization Group (TRG) to study critical phenomena and examine feasibility of accurate estimations of universal critical data for three critical points for three critical points in two dimensions …

Charge Transport And Spin Dynamics Of Color Centers In Diamond, Damon Daw

Dissertations, Theses, and Capstone Projects

Solid state defects in diamond are promising candidates for room temperature quantum information processors (1, 3, 5). Chief among these defects is the nitrogen vacancy center (‘NV center’ or ‘NV’). The NV has long coherence times (at 300K) and its state is easily initialized, manipulated and read out (5). However, the outstanding issue of entangling NV centers in a scalable fashion, at room temperature remains a challenge. This thesis presents experimental and theoretical work aimed at achieving this goal by developing the ‘flying qubit’ framework in (1). This method for remote entanglement utilizes a charge carrier (initialized into a definite …