Questioning Reality: The Progressive Development Of Modern Physics, 2024 Golda Och Academy

#### Questioning Reality: The Progressive Development Of Modern Physics, Joshua Lancman

*STEM Month*

Humanity has a tendency to divide time. The past is distinct from the present which is entirely separate from the future. In supposedly 20-20 vision history is neatly divided into different sections, distinct eras with sharp lines between them. What is present and in the future is always modern. What is past is something else with another name.

Yet time is not divided so neatly. We know this living through it: years and decades blend into one another in a non-uniform progression. To divide human history into separate eras is a necessary simplification, as it helps to ascribe order onto …

Quantum Classical Algorithm For Solving The Hubbard Model Via Dynamical Mean-Field Theory, 2024 Louisiana State University

#### Quantum Classical Algorithm For Solving The Hubbard Model Via Dynamical Mean-Field Theory, Anshumitra Baul

*LSU Doctoral Dissertations*

Modeling many-body quantum systems is widely regarded as one of the most promising applications for near-term noisy quantum computers. However, in the near term, system size limitation will remain a severe barrier for applications in materials science or strongly correlated systems. A promising avenue of research is to combine many-body physics with machine learning for the classification of distinct phases. I present a workflow that synergizes quantum computing, many-body theory, and quantum machine learning (QML) for studying strongly correlated systems. In particular, it can capture a putative quantum phase transition of the stereotypical strongly correlated system, the Hubbard model. Following …

Topics In Photonic Quantum Technology: Polarization Entanglement Dynamics In Optical Fibers And Low-Light Imaging., 2024 Louisiana State University

#### Topics In Photonic Quantum Technology: Polarization Entanglement Dynamics In Optical Fibers And Low-Light Imaging., Pratik J. Barge

*LSU Doctoral Dissertations*

Recent advances in quantum photonics promise transformative impacts on computing, communication, sensing, and imaging. This thesis explores two areas in photonic quantum technology: polarization entanglement dynamics in optical fibers and low-light imaging. Optical fibers are the most suitable medium for photonic qubits and long-distance entanglement distribution is a critical requirement to realize quantum technologies. We study the decay of polarization-entanglement of the Bell state photons propagating through imperfect optical fibers with spatially fluctuating refractive index. Furthermore, to extend the distribution distance, we propose the use of dynamical decoupling in the optical fiber using half waveplates and show that significant improvement …

Structural Factors Of An Electron As The Spinning Tetrahedral Structure Composed Of Fractional Charges, 2024 Suffolk University

#### Structural Factors Of An Electron As The Spinning Tetrahedral Structure Composed Of Fractional Charges, Polievkt Perov

*College of Arts & Sciences Faculty Works*

**Abstract**

As suggested in our papers [1,2], the elementary particles of the 1^{st} generation such as an electron, quarks, and neutral particles, are all spinning composite structures made of basic elementary particles of fractional charges +- e/3. The tetrahedral structure of an electron was suggested as one of the possible composite structures of that particle. The structure consists of one positive and four negative charges of magnitude e/3, with one positive and one negative charge located on the axis of rotation and three negative charges revolving about the axis. In this paper, the form factors such as the angles …

Superphenomena For Arbitrary Quantum Observables, 2024 Chapman University

#### Superphenomena For Arbitrary Quantum Observables, Andrew N. Jordan, Yakir Aharonov, Daniele C. Struppa, Fabrizio Colombo, Irene Sabadini, Tomer Shushi, Jeff Tollaksen, John C. Howell, A. Nick Vamivakas

*Mathematics, Physics, and Computer Science Faculty Articles and Research*

Superoscillations occur when a globally band-limited function locally oscillates faster than its highest Fourier component. We generalize this effect to arbitrary quantum-mechanical operators as a weak value, where the preselected state is a superposition of eigenstates of the operator with eigenvalues bounded to a range, and the postselection state is a local position. Superbehavior of this operator occurs whenever the operator's weak value exceeds its eigenvalue bound. We give illustrative examples of this effect for total angular momentum and energy. In the latter case, we demonstrate a sequence of harmonic oscillator potentials where a finite-energy state converges everywhere on the …

Design Of Long-Distance Entanglement Distribution Protocols For Quantum Networks, 2024 Louisiana State University at Baton Rouge

#### Design Of Long-Distance Entanglement Distribution Protocols For Quantum Networks, Stav Haldar

*LSU Doctoral Dissertations*

Future quantum technologies such as quantum communication, quantum sensing, and distributed quantum computation, will rely on networks of shared entanglement between spatially separated nodes. Distributing entanglement between these nodes, especially over long distances, currently remains a challenge, due to limitations resulting from the fragility of quantum systems, such as photon losses, non-ideal measurements, and quantum memories with short coherence times. In the absence of full-scale fault-tolerant quantum error correction, which can in principle overcome these limitations, we should understand the extent to which we can circumvent these limitations. In this work, we provide improved protocols and policies for entanglement distribution …

Generation Of Kochen-Specker Contextual Sets In Higher Dimensions By Dimensional Upscaling Whose Complexity Does Not Scale With Dimension And Their Applications, 2024 Ruder Bošković Institute

#### Generation Of Kochen-Specker Contextual Sets In Higher Dimensions By Dimensional Upscaling Whose Complexity Does Not Scale With Dimension And Their Applications, Mladen Pavičić, Mordecai Waegell

*Mathematics, Physics, and Computer Science Faculty Articles and Research*

Recently, handling of contextual sets, in particular Kochen-Specker (KS) sets, in higher dimensions has been given an increasing attention, both theoretically and experimentally. However, methods of their generation are diverse, not generally applicable in every dimension, and of exponential complexity. Therefore, we design a dimensional upscaling method, whose complexity does not scale with dimension. As a proof of principle we generate manageable-sized KS master sets in up to 27 dimensional spaces and show that well over 32 dimensions can be reached. From these master sets we obtain an ample number of smaller KS sets. We discuss three kinds of applications …

How Are Entanglement Entropies Related To Entropy Bounds?, 2024 Chapman University

#### How Are Entanglement Entropies Related To Entropy Bounds?, Emily Adlam

*Philosophy Faculty Articles and Research*

In this paper we seek to understand what current knowledge of entanglement entropies suggests about the appropriate way to interpret the covariant entropy bound. We first begin by arguing that just as in the classical case, a universal bound on the von Neumann entropy could have either an epistemic or ontological origin. We then consider several possible ways of explaining the bound as a consequence of features of the entanglement entropy. We discuss consider area laws in condensed matter and quantum field theory, arguing that they suggest an epistemic reading of the bound. We also discuss the ‘spacetime from entanglement’ …

Bridging The Geometric And Quantum Information Of Structured Light, 2024 University of Denver

#### Bridging The Geometric And Quantum Information Of Structured Light, Andrew Alexander Voitiv

*Electronic Theses and Dissertations*

In this Dissertation, we review the several advances we have developed for preparing and measuring the geometric and quantum information of structured light. The geometric phase acts as a memory of transformations undertaken by physical processes; quantum entanglement underpins quantum information science which explores the theoretical and technological applications of nonclassical correlations. Beginning with classical light, we demonstrate novel experiments and measurements of geometric phase that are enabled by spatially structuring laser beams. We then extend those concepts to complement the richer possibilities within quantum optics. Our work covers new abilities in tailoring and measuring the phase content of spatially-structured …

Quantics Tensor Trains: The Study Of A Continuous Lattice Model And Beyond, 2024 The Graduate Center, City University of New York

#### Quantics Tensor Trains: The Study Of A Continuous Lattice Model And Beyond, Aleix Bou Comas

*Dissertations, Theses, and Capstone Projects*

This four-chapter dissertation studies the efficient discretization of continuous variable functions with tensor train representation. The first chapter describes all the methodology used to discretize functions and store them efficiently. In this section, the algorithm tensor renormalization group is explained for self-containment purposes. The second chapter centers around the XY model. Quantics tensor trains are used to describe the transfer matrix of the model and compute one and two-dimensional quantities. The one dimensional magnitudes are compared to analytical results with an agreement close to machine precision. As for two dimensions, the analytical results cannot be computed. However, the critical temperature …

#### A Thesis, Or Digressions On Sculptural Practice: In Which, Concepts & Influences Thereof Are Explained, Set Forth, Catalogued, Or Divulged By Way Of Commentaries To A Poem, First Conceived By The Artist, Fed Through Chatg.P.T., And Re-Edited By The Artist, To Which Are Added, Annotated References, Impressions And Ruminations Thereof, Also Including Private Thoughts & Personal Accounts Of The Artist, Jaimie An

*Masters Theses*

This thesis is an exercise in, perhaps a futile, attempt to trace just some of the ideas, stories, and musings I might meander through in my process. It’s not quite a map, nor is it a neat catalogue; it is a haphazard collection of tickets and receipts from a travel abroad, carelessly tossed in a carry-on, only to be stashed upon returning home. These ideas are derived from much greater thinkers and authors than myself; I am a mere collector or a translator, if that, and not a very good one, for much is lost. I do not claim comprehensive …

Representation Theory And Its Applications In Physics, 2024 California Polytechnic State University, San Luis Obispo

#### Representation Theory And Its Applications In Physics, Max Varverakis

*Master's Theses*

Representation theory, which encodes the elements of a group as linear operators on a vector space, has far-reaching implications in physics. Fundamental results in quantum physics emerge directly from the representations describing physical symmetries. We first examine the connections between specific representations and the principles of quantum mechanics. Then, we shift our focus to the braid group, which describes the algebraic structure of braids. We apply representations of the braid group to physical systems in order to investigate quasiparticles known as anyons. Finally, we obtain governing equations of anyonic systems to highlight the differences between braiding statistics and conventional Bose-Einstein/Fermi-Dirac …

Multimode Metamaterial Ring Resonator As An Entangling Bus For Artificial Atoms, 2024 Syracuse University

#### Multimode Metamaterial Ring Resonator As An Entangling Bus For Artificial Atoms, Tianna Carroll

*Dissertations - ALL*

Circuit quantum electrodynamics (cQED) systems with superconducting qubits coupled to linear microwave resonators are a prominent platform for realizing scalable quantum information processors. Combining cQED architectures with multimode resonators leads to a broad set of applications for performing analog quantum simulation, implementing dense quantum memory, and generating multimode entangled states between physically distant qubits. Microwave resonators in cQED are typically formed from distributed transmission lines that exhibit conventional dispersion with harmonic mode spacing; in such systems, usually only a single resonant mode can be strongly coupled to a qubit. Superconducting metamaterial resonators comprised of lumped circuit elements can be designed …

Entanglement With Neutral Atoms In The Simulation Of Nonequilibrium Dynamics Of One-Dimensional Spin Models, 2024 University of New Mexico - Main Campus

#### Entanglement With Neutral Atoms In The Simulation Of Nonequilibrium Dynamics Of One-Dimensional Spin Models, Anupam Mitra

*Physics & Astronomy ETDs*

Quantum entanglement is a key ingredient for quantum information processing with capabilities beyond that of classical computation. We study the generation and role of entanglement in the dynamics of spin-1/2 models, both for the design of quantum gates for general-purpose quantum computation and for quantum simulation of interacting spin models. We introduce the neutral atom Mølmer-Sørensen gate, involving rapid adiabatic Rydberg dressing interleaved in a spin-echo sequence. We show its robustness to quasi-static experimental imperfections and favorable scaling with the time-energy scales of Rydberg-mediated entanglement generation. In quantum simulation, we consider critical behavior in quench dynamics of transverse field Ising …

A Realist Interpretation Of Unitarity In Quantum Gravity, 2024 Chapman University

#### A Realist Interpretation Of Unitarity In Quantum Gravity, Indrajit Sen, Stephon Alexander, Justin Dressel

*Mathematics, Physics, and Computer Science Faculty Articles and Research*

Unitarity is a difficult concept to implement in canonical quantum gravity because of state non-normalisability and the problem of time. We take a realist approach based on pilot-wave theory to address this issue in the Ashtekar formulation of the Wheeler–DeWitt equation. We use the postulate of a definite configuration in the theory to define a global time for the gravitational-fermionic system recently discussed in Alexander *et al* (2022 *Phys. Rev.* D **106** 106012), by parameterising a variation of a Weyl-spinor that depends on the Kodama state. The total Hamiltonian constraint yields a time-dependent Schrodinger equation, without semi-classical approximations, which we …

Improving The Scalability Of Neural Network Surface Code Decoders, 2024 William & Mary

#### Improving The Scalability Of Neural Network Surface Code Decoders, Kevin Wu

*Undergraduate Honors Theses*

Quantum computers have recently gained significant recognition due to their ability to solve problems intractable to classical computers. However, due to difficulties in building actual quantum computers, they have large error rates. Thus, advancements in quantum error correction are urgently needed to improve both their reliability and scalability. Here, we first present a type of topological quantum error correction code called the surface code, and we discuss recent developments and challenges of creating neural network decoders for surface codes. In particular, the amount of training data needed to reach the performance of algorithmic decoders grows exponentially with the size of …

Learning, Optimizing, And Simulating Fermions With Quantum Computers, 2024 University of New Mexico

#### Learning, Optimizing, And Simulating Fermions With Quantum Computers, Andrew Zhao

*Physics & Astronomy ETDs*

Fermions are fundamental particles which obey seemingly bizarre quantum-mechanical principles, yet constitute all the ordinary matter that we inhabit. As such, their study is heavily motivated from both fundamental and practical incentives. In this dissertation, we will explore how the tools of quantum information and computation can assist us on both of these fronts. We primarily do so through the task of partial state learning: tomographic protocols for acquiring a reduced, but sufficient, classical description of a quantum system. Developing fast methods for partial tomography addresses a critical bottleneck in quantum simulation algorithms, which is a particularly pressing issue for …

Towards Continuous Variable Quantum Computation Of Lattice Gauge Theories, 2024 University of Tennessee, Knoxville

#### Towards Continuous Variable Quantum Computation Of Lattice Gauge Theories, Shane Nicklaus Thompson

*Doctoral Dissertations*

The calculation of physical quantities in a relativistic quantum field theory (rQFT) is a computationally demanding task due to the presence of an infinite number of degrees of freedom. This problem carries over to discretized versions of these theories, i.e. lattice field theories, where the Hilbert space size increases exponentially with the size of the lattice. Despite the success of some classical techniques such as Monte Carlo, their applicability is limited. For instance, Monte Carlo is associated with a sign problem that makes real-time evolution and high-fermion-density systems particularly challenging to compute. Quantum computation is a promising avenue thanks to …

Experimental Quantum Key Distribution In Turbulent Channels, 2024 University of Tennessee, Knoxville

#### Experimental Quantum Key Distribution In Turbulent Channels, Kazi Mh Reaz

*Doctoral Dissertations*

Quantum Key Distribution (QKD) ensures security by relying on the laws of quantum physics rather than the mathematical intricacy of encryption algorithms. The transmission medium is a critical restricting factor for any quantum communication protocol. Fiber-based optical networks suffer great losses, making quantum communication impossible beyond metropolitan scales. Here free-space quantum communication can be a great alternative for long-distance communication. Even though modern Communications are mostly wireless the atmosphere poses a challenge for QKD. So QKD must be resistant to both atmospheric loss and variations in transmittance. In this thesis we conduct an experiment to strengthen the BB84 protocol's resistance …

The Search For Photonuclear Interactions Of Muons Utilizing Test Beam Data At The Large Hadron Collider, 2024 University of Texas at Arlington

#### The Search For Photonuclear Interactions Of Muons Utilizing Test Beam Data At The Large Hadron Collider, Miranda M. Williams

*2024 Spring Honors Capstone Projects*

The ATLAS Detector is one of four different types of detectors within the Large Hadron Collider and is used to study the fundamental theories of the universe. Within the ATLAS experiment, beams of known composition and energies – otherwise known as “test beams” – are one of the many methods used to study specific physical phenomena. In this study, a test beam of muons with an energy of 160 GeV was analyzed to search for evidence of photonuclear interactions. This necessitated analyzing and filtering over 50,000 total events using specific parameters that would indicate such an event had occurred. To …