Quantum Physics Commons^™

Comparisons Of Performance Between Quantum And Classical Machine Learning, Christopher Havenstein, Damarcus Thomas, Swami Chandrasekaran

SMU Data Science Review

In this paper, we present a performance comparison of machine learning algorithms executed on traditional and quantum computers. Quantum computing has potential of achieving incredible results for certain types of problems, and we explore if it can be applied to machine learning. First, we identified quantum machine learning algorithms with reproducible code and had classical machine learning counterparts. Then, we found relevant data sets with which we tested the comparable quantum and classical machine learning algorithm's performance. We evaluated performance with algorithm execution time and accuracy. We found that quantum variational support vector machines in some cases had higher accuracy …

Hybrid Excitations In Organic-Semiconductor Materials, David W. Facemyer

Theses, Dissertations and Capstones

It has been suggested theoretically and realized experimentally that combining organic material and inorganic semiconductors in one heterostructure would result in resonant interactions between the Frenkel excitons in the organic material and the Wannier-Mott excitons in the semiconductors, leading to the formation of an exciton hybridization state. The new materials, possessing the complimentary characteristics of both exciton types, such as large exciton radius, enormous oscillator strength and room-temperature operation properties, would enhance optical nonlinearities and promise to have useful applications in both the field of Bose-Einstein condensation of polaritons and polariton lasers. In this work, we consider a strong coupling …

Using Fundamental Properties Of Light To Investigate Photonic Effects In Condensed Matter And Biological Tissues, Laura A. Sordillo

Dissertations and Theses

Light possesses characteristics such as polarization, wavelength and coherence. The interaction of light and matter, whether in a semiconductor or in a biological sample, can reveal important information about the internal properties of a system. My thesis focuses on two areas: photocarriers in gallium arsenide and biomedical optics. Varying the excitation wavelength can be used to study both biological tissue and condensed matter. I altered the excitation wavelengths to be in the longer near-infrared (NIR) optical windows, in the shortwave infrared (SWIR) range, a wavelength region previously thought to be unusable for medical imaging. With this method, I acquired high …

An Introduction To Supersymmetric Quantum Mechanics, Vincent R. Siggia

Theses and Dissertations

In this thesis, the general framework of supersymmetric quantum mechanics and the path integral approach will be presented (as well as the worked out example of the supersymmetric harmonic oscillator). Then the theory will be specialized to the case of supersymmetric quantum mechanics on Riemannian manifolds, which will start from a supersymmetric Lagrangian for the general case and the special case for S2. Afterwards, there will be a discussion on the superfield formalism. Concluding this thesis will be the Hamiltonian formalism followed by the inclusion of deforma- tions by potentials.

New Perspectives On The Schrödinger-Pauli Theory Of Electrons: Part Ii: Application To The Triplet State Of A Quantum Dot In A Magnetic Field, Marlina Slamet, Viraht Sahni

Publications and Research

The Schrödinger-Pauli (SP) theory of electrons in the presence of a static electromagnetic field can be described from the perspective of the individual electron via its equation of motion or 'Quantal Newtonian' first law. The law is in terms of 'classical' fields whose sources are quantum-mechanical expectation values of Hermitian operators taken with respect to the wave function. The law states that the sum of the external and internal fields experienced by each electron vanishes. The external field is the sum of the binding electrostatic and Lorentz fields. The internal field is the sum of fields representative of properties of …

Theoretical Studies Of The Structure And Stability Of Metal Chalcogenide Crntem (1≤N≤6, 1≤M≤8) Clusters, Fnu Sweta Prabha

Theses and Dissertations

In the presented work, first principle studies on electronic structure, stability, and magnetic properties of metal chalcogenide, Cr_nTe_m clusters have been carried out within a density functional framework using generalized gradient functions to incorporate the exchange and correlation effects. The energetic and electronic stability was investigated, and it was found that they are not always correlated as seen in the cluster Cr₆Te₈ which has smaller gap between its HOMO (Highest Occupied Molecular Orbital) and LUMO (Lowest Unoccupied Molecular Orbital) and a high electron affinity of 3.39 eV indicating lower electronic stability whereas higher fragmentation …

Three-Particle Systems With Resonant Subprocesses In A Finite Volume, Raúl A. Briceño, Maxwell T. Hansen, Stephen R. Sharpe

Physics Faculty Publications

In previous work, we have developed a relativistic, model-independent three-particle quantization condition, but only under the assumption that no poles are present in the two-particle K matrices that appear as scattering subprocesses [M. T. Hansen and S. R. Sharpe, Phys. Rev. D 90, 116003 (2014); M. T. Hansen and S. R. Sharpe, Phys. Rev. D 92, 114509 (2015); R. A. Briceño et al., Phys. Rev. D 95, 074510 (2017).]. Here we lift this restriction, by deriving the quantization condition for identical scalar particles with a G-parity symmetry, in the case that the two-particle K matrix has a pole in the …

New Perspectives On The Schrödinger-Pauli Theory Of Electrons: Part I, Viraht Sahni

Publications and Research

Schrödinger-Pauli (SP) theory is a description of electrons in the presence of a static electromagnetic field in which the interaction of the magnetic field with both the orbital and spin moments is explicitly considered. The theory is described from the new perspective of the individual electron via its equation of motion or ‘Quantal Newtonian’ first law. The law is in terms of ‘classical’ fields whose sources are quantum mechanical expectation values of Hermitian operators taken with respect to the system wave function. The law states that each electron experiences an external and an internal field, the sum of which vanish. …

Exploring The Structure Of The Bound Proton With Deeply Virtual Compton Scattering, M. Hattawy, N. A. Baltzell, R. Dupré, S. Bültmann, B. Torayev, G. Gavalian, F. Hauenstein, S. E. Kuhn, M. Khachatryan, M. Mayer, J. Poudel, Y. Prok, L. B. Weinstein, J. Zhang, Z. W. Zhao, Clas Collaboration

Physics Faculty Publications

In the past two decades, deeply virtual Compton scattering of electrons has been successfully used to advance our knowledge of the partonic structure of the free proton and investigate correlations between the transverse position and the longitudinal momentum of quarks inside the nucleon. Meanwhile, the structure of bound nucleons in nuclei has been studied in inclusive deep-inelastic lepton scattering experiments off nuclear targets, showing a significant difference in longitudinal momentum distribution of quarks inside the bound nucleon, known as the EMC effect. In this Letter, we report the first beam spin asymmetry (BSA) measurement of exclusive deeply virtual Compton scattering …

Searching For Clean Observables In $B -> D* /Tau- \Bar{\Nu}_{\Tau}$ Decays, Michael D. Williams Jr.

Theses and Dissertations

In this thesis, the clean angular observables in the $\bar{B} \to D^{*+} \ell^- \bar{\nu}_{\ell}$ angular distribution is studied. Similar angular observables are widely studied in $B \to K^* \mu^+ \mu^-$ decays. We believed that these angular observables may have different sensitivities to different new physics structures.

Polarized Hyperon Production In Single-Inclusive Electron Positron Annihilation At Next-To-Leading Order, Leonard Gamberg, Zhong-Bo Kang, Daniel Pitonyak, Marc Schlegel, Shinsuke Yoshida

Physics Faculty Publications

We study the production of polarized A-hyperons in electron-positron annihilation. We are particularly interested in the transverse-spin dependence of the cross section for unpolarized incident electron-positron pairs. At high energies this process may be described in the collinear twist-3 framework, where the hadronization transition of partons into a transversely polarized -hyperon can be written in terms of collinear twist-3 fragmentation matrix elements. We calculate the hard partonic cross sections and interference terms in perturbative QCD to next-to-leading order accuracy. We find that the QCD equation of motion plays a crucial role in our analysis. As a byproduct, assuming the validity …

Quark-Mass Dependence Of Elastic Πk Scattering From Qcd, David J. Wilson, Raúl A. Briceño, Jozef K. Dudek, Robert G. Edwards, Christopher E. Thomas

Physics Faculty Publications

We present a determination of the isospin-1/2 elastic πK scattering amplitudes in S and P partial waves using lattice quantum chromodynamics. The amplitudes, constrained for a large number of real-valued energy points, are obtained as a function of light-quark mass, corresponding to four pion masses between 200 and 400 MeV, at a single lattice spacing. Below the first inelastic threshold, the P-wave scattering amplitude is dominated by a single pole singularity that evolves from being a stable bound state at the highest quark mass into a narrow resonance that broadens as the pion and kaon masses are reduced. As in …

Finite Volume Matrix Elements Of Two-Body States, Alessandro Baroni, Raúl A. Briceño, Maxwell T. Hansen, Filipe G. Ortega-Gama

Physics Faculty Publications

In this talk, we present a framework for studying structural information of resonances and bound states coupling to two-hadron scattering states. This makes use of a recently proposed finite-volume formalism to determine a class of observables that are experimentally inaccessible but can be accessed via lattice QCD. In particular, we shown that finite-volume two-body matrix elements with one current insertion can be directly related to scattering amplitudes coupling to the external current. For two-hadron systems with resonances or bound states, one can extract the corresponding form factors of these from the energy-dependence of the amplitudes.

Progress Report On The Relativistic Three-Particle Quantization Condition, Tyler D. Blanton, Raúl A. Briceño, Maxwell T. Hanson, Fernando Romero-Lopez, Stephen R. Sharpe

Physics Faculty Publications

We describe recent work on the relativistic three-particle quantization condition, generalizing and applying the original formalism of Hansen and Sharpe, and of Briceño, Hansen and Sharpe. In particular, we sketch three recent developments: the generalization of the formalism to include K-matrix poles; the numerical implementation of the quantization condition in the isotropic approximation; and ongoing work extending the description of the three-particle divergence-free K matrix beyond the isotropic approximation.

Pdfs In Small Boxes, Raúl A. Briceño, Juan V. Guerrero, Maxwell T. Hansen, Christopher J. Monahan

Physics Faculty Publications

PDFs can be studied directly using lattice QCD by evaluating matrix elements of non-local operators. A number of groups are pursuing numerical calculations and investigating possible systematic uncertainties. One systematic that has received less attention is the effect of calculating in a finite spacetime volume. Here we present first attempts to assess the role of the finite volume for spatially non-local operators. We find that these matrix elements may suffer from large finite-volume artifacts and more careful investigation is needed.

The Us Electron Ion Collider Accelerator Designs, A. Seryi, S.V. Benson, S.A. Bogacz, P.D. Brindza, M.W. Brucker, A. Camsonne, E. Daly, P.V. Degtiarenko, Y.S. Derbenev, M. Diefenthaler, J. Dolbeck, R. Ent, R. Fair, D. Fazenbaker, Y. Furletova, B.R. Gamage, D. Gaskell, R.L. Geng, P. Ghoshal, R.C. York, Et Al.

Physics Faculty Publications

With the completion of the National Academies of Sciences Assessment of a US Electron-Ion Collider, the prospects for construction of such a facility have taken a step forward. This paper provides an overview of the two site-specific EIC designs: JLEIC (Jefferson Lab) and eRHIC (BNL) as well as brief overview of ongoing EIC R&D.

Quantum Entanglement Of One-Dimensional Spinless Fermions, Emanuel Casiano-Diaz

Graduate College Dissertations and Theses

The constituents of a quantum many-body system can be inextricably linked, a phenomenon known as quantum entanglement. Entanglement can be used as a resource for quantum computing, quantum communication and detecting phase transitions, among others. The amount of entanglement can be quantified via the von Neumann and Rényi entropies, which have their origins in information theory.

In this work, the quantum entanglement between subsystems of a one dimen- sional lattice model of fermions is quantified. The von Neumann and Rényi entropies were calculated for two types of subsystems. In the first study, the subsystems were treated as two subsets of …

Quantum Isometry Group Of Deformation: A Counterexample, Debashish Goswami, Arnab Mandal

Journal Articles

We give a counterexample to show that the quantum isometry group of a deformed finite dimensional spectral triple may not be isomorphic with a deformation of the quantum isometry group of the undeformed spectral triple.

Environmental Effects On Nonlocal Correlations, Tamal Guha, Bihalan Bhattacharya, Debarshi Das, Some Sankar Bhattacharya, Amit Mukherjee, Arup Roy, Kaushiki Mukherjee, Nirman Ganguly, A. S. Majumdar

Journal Articles

Environmental interactions are ubiquitous in practical instances of any quantum information processing protocol. The interaction results in depletion of various quantum resources and even complete loss in numerous situations. Nonlocality, which is one particular quantum resource marking a significant departure of quantum mechanics from classical mechanics, meets the same fate. In the present work we study the decay in nonlocality to the extent of the output state admitting a local hidden state model. Using some fundamental quantum channels we also demonstrate the complete decay in the resources in the purview of the Bell–Clauser– Horne–Shimony–Holt inequality and a three-settings steering inequality. …

Physics And Applications Of Exceptional Points, Qi Zhong

Dissertations, Master's Theses and Master's Reports

Exceptional points (EPs) are singularities that arise in non-Hermitian physics. Crossing EPs is believed to be related with phase transitions between parity-time-(PT-)symmetric phase and broken PT phase. Owing to their peculiar topology, EPs can remotely induce observable effects when encircled by closed trajectories in the parameter space. In this dissertation, first of all, we investigate the extreme dynamics of non-Hermitian systems near higher order EPs constructed using the bosonic algebra method. The strong power oscillations for certain initial conditions can occur as a result of the peculiar eigenspace geometry and its dimensionality collapse near these singularities. And in the PT …