Open Access. Powered by Scholars. Published by Universities.®
Physical Sciences and Mathematics Commons™
Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 9 of 9
Full-Text Articles in Physical Sciences and Mathematics
Ultrafast Optical Control And Characterization Of Carrier And Spin Dynamics In Novel Magnetic Topological Insulator Systems, Peiwen Liu
Dissertations, Theses, and Masters Projects
Magnetic topological insulators (MTIs) are of considerable interest in developing novel spintronics and quantum computing applications. Under the topological protection by time-reversal Z2 invariant number, magnetic topological insulators are provided with robust electronic and magnetic properties against local perturbations. The quantum anomalous Hall effect (QAHE), which harbors dissipationless chiral edge states in MTIs, provides a competitive platform for future low-power consumption and high-speed spintronic devices. Although the present studies on both bulk and surface magnetic properties in MTIs have made significant progress, the in-depth understanding of the exchange couplings and the interaction between the two magnetization sources is far from …
Proton Spin Structure From Simultaneous Monte Carlo Global Qcd Analysis, Yiyu Zhou
Proton Spin Structure From Simultaneous Monte Carlo Global Qcd Analysis, Yiyu Zhou
Dissertations, Theses, and Masters Projects
Despite the great effort and achievements made towards understanding proton spin structure in the past few decades, a complete picture is still elusive. Parton distribution functions (PDFs), which in quantum chromodynamics (QCD) encode the momentum and helicity distributions of quarks and gluons inside a proton, provide the means by which to quantify the proton structure information. Being inherently nonperturbative, PDFs have to be extracted from unpolarized and polarized lepton-hadron and hadron-hadron scattering data. In particular, experiments that measure unpolarized and polarized jet observables can provide insight into the momentum and helicity distributions of gluons, which have generally been more difficult …
Light-Matter Interactions In Quasi-Two-Dimensional Geometries, David James Lahneman
Light-Matter Interactions In Quasi-Two-Dimensional Geometries, David James Lahneman
Dissertations, Theses, and Masters Projects
Emergent phenomena that occur at length scales smaller than approximately half the wavelength of light cannot be resolved by conventional optical techniques due to the Abbe diffraction limit. Scattering-type scanning near-field infrared microscopy (S-SNIM) can circumvent this diffraction limit allowing infrared spectroscopy at nano-scale dimensions independent of the wavelength. Additionally, there is enhanced surface sensitivity resulting from this nanoconfinement of infrared light. S-SNIM is uniquely suitable to study a diverse range of material properties inaccessible by far-field optics in the infrared such as the optical properties of ultrathin films as well as hybrid light matter surface waves called polaritons. Initially, …
Excited J-- Resonances In Meson-Meson Scattering From Lattice Qcd, Christopher Johnson
Excited J-- Resonances In Meson-Meson Scattering From Lattice Qcd, Christopher Johnson
Dissertations, Theses, and Masters Projects
Understanding the excited light meson spectrum is vital to our understanding of how quarks and gluons bind to become hadrons. This sector is home to a plethora of states including hadrons laying outside the quark model. Distinguishing the from the rest of the spectrum would be made easier if we first had a handle on the light quark anti-quark spectrum. I present the first determination of excited light JPC=1--,2--,3-- resonances in meson-meson scattering at the SU(3) flavor point from lattice QCD. This system can be described in the context of pseudoscalar-vector elastic scattering and I determine two 1-- resonances; a …
Forward & Off-Forward Parton Distributions From Lattice Qcd, Colin Paul Egerer
Forward & Off-Forward Parton Distributions From Lattice Qcd, Colin Paul Egerer
Dissertations, Theses, and Masters Projects
The interpretation of (semi-)inclusive and certain exclusive scattering processes relies on the factorization of hard parton level cross sections from long-range and non-perturbative parton correlations. The familiar Parton Distribution Functions (PDFs) and Generalized Parton Distributions quantify the non-perturbative dynamics in these situations and address a number of key questions surrounding the structure of hadrons. A certain class of matrix elements accessible in lattice QCD, so called Lattice Cross Sections, have been shown to factorize into these collinear distributions in a manner akin to the factorization of hadronic cross sections. In the short-distance regime, matrix elements of space-like separated two-current operators …
Ac & Dc Zeeman Interferometric Sensing With Ultracold Trapped Atoms On A Chip, Shuangli Du
Ac & Dc Zeeman Interferometric Sensing With Ultracold Trapped Atoms On A Chip, Shuangli Du
Dissertations, Theses, and Masters Projects
This thesis presents progress in developing a trapped atom interferometer on a chip, based on AC Zeeman potentials. An atom interferometer is a high-precision measuring tool that can detect various types of forces and potentials. The trapped atom interferometer introduced in this thesis targets the shortcomings of traditional ballistic atom interferometers, which are typically meter-scale in height. Notably, a trapped atom interferometer has a localized atomic sample, a potentially longer interferometric phase accumulation time, and the prospect of being the basis for a more compact instrument. This thesis presents multiple projects in the development of a trapped atom interferometer based …
Calculation Of Gluon Pdf In The Nucleon Using Pseudo-Pdf Formalism With Wilson Flow Technique In Lqcd, Md Tanjib Atique Khan
Calculation Of Gluon Pdf In The Nucleon Using Pseudo-Pdf Formalism With Wilson Flow Technique In Lqcd, Md Tanjib Atique Khan
Dissertations, Theses, and Masters Projects
A comprehensive study of the gluonic content in the nucleon from a first principles lattice quantum chromodynamics calculation is presented. The unpolarized gluonic distribution in the nucleon is calculated using the pseudo-PDF framework on the lattice. First, the spectral analyses of the low-lying states in the nucleon, as well as in the delta are performed on the lattice, identifying baryons states with hybrid characteristics, in which the gluons play a manifestly structural role, and determining a set of operators which have significant overlaps onto the ground state of the nucleon. Techniques such as distillation for smearing the quark fields, momentum …
Radiofrequency Ac Zeeman Trapping For Neutral Atoms, Andrew Peter Rotunno
Radiofrequency Ac Zeeman Trapping For Neutral Atoms, Andrew Peter Rotunno
Dissertations, Theses, and Masters Projects
This thesis presents the first experimental demonstration of a two-wire AC Zeeman trap on an atom chip. The AC Zeeman energy is a resonant, bipolar, state-dependent atomic energy shift produced by alternating magnetic fields with frequencies near hyperfine transitions. We demonstrate that high gradients in this energy, as near an atom chip, can produce a spin-state selective force greater than gravity for ultracold rubidium atoms. Our novel trap is generated by a local minimum in AC Zeeman energy. Using less than one watt of power, we demonstrate trap frequency on the order of a few hundred Hz, trap depth about …
Dihadron Beam Spin Asymmetries On An Unpolarized Hydrogen Target With Clas12, Timothy Barton Hayward
Dihadron Beam Spin Asymmetries On An Unpolarized Hydrogen Target With Clas12, Timothy Barton Hayward
Dissertations, Theses, and Masters Projects
The semi-inclusive deep inelastic scattering process, where an electron scatters off a proton target at high enough energy that the process can be described by the scattering off a single constituent particle, offers targeted access to the internal structure of the nucleon. The process can be described in two phases by parton distribution functions (PDFs), which describe the likelihood of finding a quark or gluon in a particular state inside of the nucleon and then by fragmentation functions (FFs) which describe the likelihood of forming a particular final state particle. One way to study these properties is via the measurement …