Quantum Physics Commons^™

Classification Of Pixel Tracks To Improve Track Reconstruction From Proton-Proton Collisions, Kebur Fantahun, Jobin Joseph, Halle Purdom, Nibhrat Lohia

SMU Data Science Review

In this paper, machine learning techniques are used to reconstruct particle collision pathways. CERN (Conseil européen pour la recherche nucléaire) uses a massive underground particle collider, called the Large Hadron Collider or LHC, to produce particle collisions at extremely high speeds. There are several layers of detectors in the collider that track the pathways of particles as they collide. The data produced from collisions contains an extraneous amount of background noise, i.e., decays from known particle collisions produce fake signal. Particularly, in the first layer of the detector, the pixel tracker, there is an overwhelming amount of background noise that …

Methods For Bioconjugation Of Biochemical Sensors Based On Metallic Nanoparticles, Jacob Rolin

Summer Community of Scholars Posters (RCEU and HCR Combined Programs)

No abstract provided.

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 …

Wideband And Relativistic Superradiance In Astrophysics, Christopher M. Wyenberg

Electronic Thesis and Dissertation Repository

In the quantum phenomenon of superradiance (SR) a population of inverted particles evolves, through its interaction with the quantized vacuum radiation field, into a highly entangled state capable of generating much greater radiative emission than predicted by the independent spontaneous decay of its constituent particles. The phenomenon has recently been applied to transient astrophysical processes but has thus far been restricted to particles sharing a common velocity. This thesis researches the effects of astrophysical velocity distributions upon SR, which are distinct from conventional regimes of the quantum optics literature in that they may possess extremely wide bandwidths, turbulent statistical properties, …

Magnetic Skyrmions Unwrapped, Alexey Kovalev

Alexey Kovalev Papers

Experiments with chiral magnets may hold the key to a better understanding of fundamental aspects of transformations between different skyrmionic states, necessary for magnetic memory and logic applications to become a reality.

With the aim of developing computing devices that operate with low power dissipation, scientists have been pursuing the idea of encoding information in magnetic states. Specifically, skyrmions, which can be thought of as whirl-like states of magnetic moments, are promising candidates for this purpose. The advantage of skyrmions lies in their topological protection, a property implying that only a ‘global’ system modification can erase a skyrmion. Realizations of …

Characterizing The Single-Photon State: Quantum Physics Experiments With Single-Photon Sensitivity, Sheldon Lee Field

University Honors Theses

Coincidence-counting and spontaneous parametric downconversion are central to introductory quantum mechanical experimentation but have remained largely out of reach of undergraduate physics instructors. This thesis summarizes the theory behind light polarization, spontaneous parametric downconversion, birefringent refractive indices, and an affordable self-contained photon coincidence counting unit (CCU). A method for implementing a CCU to demonstrate downconversion is presented, and empirical results are provided.

Quantum Computational Simulations For Condensed Matter Systems, Trevor Alan Keen

Doctoral Dissertations

In condensed matter physics, and especially in the study of strongly correlated electron systems, numerical simulation techniques are crucial to determine the properties of the system including interesting phases of matter that arise from electron-electron interactions. Many of these interesting phases of matter, including but not limited to Mott-insulating materials and possibly high-temperature superconducting systems, can be modeled by the Hubbard model. Although it is one of the simplest models to include electron-electron interactions, it cannot be solved analytically in more than one dimension and thus numerical techniques must be employed. Although there have been great strides in classical numerical …

Overcoming Atmospheric Effects In Quantum Cryptography, Brian Joseph Rollick

Doctoral Dissertations

Quantum Computers will have the potential to greatly assist us in problems such as searching, optimization and even drug discovery. Unfortunately, among these newfound capabilities is one which allows one to break RSA encryption in orders of magnitude less time. One promising countermeasure to secure our communication today and in the future is the one time pad, although it is very difficult to generate and distribute. Quantum Key Distribution offers a practical method for two authenticated parties to generate a key. Whereby the parties, Alice and Bob, share quantum states and use physical laws to place an upper bound on …

Optimization Of Quantum Circuits Using Spin Bus Multiqubit Gates For Quantum Dots, Miguel Gonzalo Rodriguez

Open Access Theses & Dissertations

The current conventional method for designing quantum circuits is to employ a number of single- and two-qubit gates, which often necessitate a lengthy sequence, imposing severe constraints on quantum coherence and quantum circuit complexity. Coupling multiple spin qubits to a common spin chain can result in a generically multiqubit gate. It is demonstrated that the multiqubit gate can substantially reduce the depth of quantum circuits and establish multiqubit entanglement considerably more quickly.

Quantum Computing Simulation Of The Hydrogen Molecule System With Rigorous Quantum Circuit Derivations, Yili Zhang

All Graduate Plan B and other Reports

Quantum computing has been an emerging technology in the past few decades. It utilizes the power of programmable quantum devices to perform computation, which can solve complex problems in a feasible time that is impossible with classical computers. Simulating quantum chemical systems using quantum computers is one of the most active research fields in quantum computing. However, due to the novelty of the technology and concept, most materials in the literature are not accessible for newbies in the field and sometimes can cause ambiguity for practitioners due to missing details.

This report provides a rigorous derivation of simulating quantum chemistry …

Quantum Dots In Two-Dimensional Tungsten Diselenide, Jeb Allen Michael Stacy

Graduate Theses and Dissertations

This work focuses on the investigation of single and double quantum dots in two-dimensional transition metal dichalcogenide tungsten diselenide (WSe_2) as a means to evaluate the valley degree of freedom as a potential qubit and ambipolar tungsten diselenide monolayers as single photon sources. Gate-defined quantum dots in monolayer and bilayer WSe_2 were fabricated and characterized. Single dot devices are gated from above and below the WSe_2 to accumulate a hole gas. Temperature dependence of Coulomb-blockade peak height is consistent with single-level transport. Excited-state transport in the quantum dot is shown for both monolayer and bilayer devices. Magnetic field dependence of …

Quantum Transport And Electric-Field Effects In Layered Topological Semimetals And Magnetic Materials, Arash Fereidouni Ghaleh Minab

Graduate Theses and Dissertations

This dissertation describes transport experiments on quantum devices in layered Dirac nodal line topological semimetals and antiferromagnetic materials down to a few layers. We used gate-induced effects to alter the transport properties of these materials.

First, we introduced current annealing in topological semimetals to achieve high-quality devices. We demonstrate current annealing to substantially improve the electronic transport properties of 2D topological semimetal flakes. Contact resistance and resistivity were improved by factors up to 2,000,000 and 20,000, respectively, in devices based on exfoliated flakes of two topological semimetals, ZrSiSe and BaMnSb2. Using this method, carrier mobility in ZrSiSe improved by a …

Majorana Bound States With Chiral Magnetic Textures, Utkan Güngördü, Alexey Kovalev

Alexey Kovalev Papers

The aim of this Tutorial is to give a pedagogical introduction into realizations of Majorana fermions, usually termed as Majorana bound states (MBSs), in condensed matter systems with magnetic textures. We begin by considering the Kitaev chain model of “spinless” fermions and show how two “half” fermions can appear at chain ends due to interactions. By considering this model and its two-dimensional generalization, we emphasize intricate relation between topological superconductivity and possible realizations of MBS. We further discuss how “spinless” fermions can be realized in more physical systems, e.g., by employing the spin-momentum locking. Next, we demonstrate how magnetic textures …

Majorana Bound States With Chiral Magnetic Textures, Utkan Güngördü, Alexey Kovalev

Faculty Publications, Department of Physics and Astronomy

The aim of this Tutorial is to give a pedagogical introduction into realizations of Majorana fermions, usually termed as Majorana bound states (MBSs), in condensed matter systems with magnetic textures. We begin by considering the Kitaev chain model of “spinless” fermions and show how two “half” fermions can appear at chain ends due to interactions. By considering this model and its two-dimensional generalization, we emphasize intricate relation between topological superconductivity and possible realizations of MBS. We further discuss how “spinless” fermions can be realized in more physical systems, e.g., by employing the spin-momentum locking. Next, we demonstrate how magnetic textures …

Weakness Of Weak Values: Incompatibility Of Anomalous Pulse-Spectrum Amplification And Optical Frequency Combs, John C. Howell

Mathematics, Physics, and Computer Science Faculty Articles and Research

We probe the use of optical frequency combs to place lower bounds on anomalous amplification of a weak-value-measured pulse delay, potentially reaching a theoretical temporal resolution of better than 10⁻³⁴ s. Owing to the interferometric behavior of weak values, we show that anomalous weak value amplification of a time delay is not equivalent to a temporal linear phase ramp. We show that the anomalous weak value is a rearrangement of amplitudes that generates an apparent shift that can be measured in direct detection, but does not change the actual frequency offset of a spectral distribution measurable in coherent detection. …

On Superoscillations And Supershifts In Several Variables, Yakir Aharonov, Fabrizio Colombo, Andrew N. Jordan, Irene Sabadini, Tomer Shushi, Daniele C. Struppa, Jeff Tollaksen

Mathematics, Physics, and Computer Science Faculty Articles and Research

The aim of this paper is to study a class of superoscillatory functions in several variables, removing some restrictions on the functions that we introduced in a previous paper. Since the tools that we used with our approach are not common knowledge we will give detailed proof for the case of two variables. The results proved for superoscillatory functions in several variables can be further extended to supershifts in several variables.

Monitoring Fast Superconducting Qubit Dynamics Using A Neural Network, G. Koolstra, N. Stevenson, S. Barzili, L. Burns, K. Siva, S. Greenfield, W. Livingston, A. Hashim, R. K. Naik, J. M. Kreikebaum, K. P. O'Brien, D. I. Santiago, Justin Dressel, I. Siddiqi

Mathematics, Physics, and Computer Science Faculty Articles and Research

Weak measurements of a superconducting qubit produce noisy voltage signals that are weakly correlated with the qubit state. To recover individual quantum trajectories from these noisy signals, traditional methods require slow qubit dynamics and substantial prior information in the form of calibration experiments. Monitoring rapid qubit dynamics, e.g., during quantum gates, requires more complicated methods with increased demand for prior information. Here, we experimentally demonstrate an alternative method for accurately tracking rapidly driven superconducting qubit trajectories that uses a long short-term memory (LSTM) artificial neural network with minimal prior information. Despite few training assumptions, the LSTM produces trajectories that include …

Characterization Of Electrophoretic Deposited Zinc Oxide Nanopartices For The Fabrication Of Next-Generation Nanoscale Electronic Applications, Fawwaz Abduh A. Hazzazi

LSU Doctoral Dissertations

Several reports state that it is crucial to analyze nanoscale semiconductor materials and devices with potential benefits to meet the need for next-generation nanoelectronics, bio, and nanosensors. The progress in the electronics field is as significant now, with modern technology constantly evolving and a greater focus on more efficient robust optoelectronic applications. This dissertation focuses on the study and examination of the practicality of Electrophoretic Deposition (EPD) of zinc oxide (ZnO) nanoparticles (NPs) for use in semiconductor applications.

The feasibility of several synthesized electrolytes, with and without surfactants and APTES surface functionalization, is discussed. The primary objective of this study …

What Is A Photon? Foundations Of Quantum Field Theory, Charles G. Torre

All Physics Faculty Publications

This is a brief, informal, and relatively low-level course on the foundations of quantum field theory. The prerequisites are undergraduate courses in quantum mechanics and electromagnetism.

Methodologies For Quantum Circuit And Algorithm Design At Low And High Levels, Edison Tsai

Dissertations and Theses

Although the concept of quantum computing has existed for decades, the technology needed to successfully implement a quantum computing system has not yet reached the level of sophistication, reliability, and scalability necessary for commercial viability until very recently. Significant progress on this front was made in the past few years, with IBM planning to create a 1000-qubit chip by the end of 2023, and Google already claiming to have achieved quantum supremacy. Other major industry players such as Intel and Microsoft have also invested significant amounts of resources into quantum computing research.

Any viable computing system requires both hardware and …