Quantum Algorithms With Applications To Simulating Physical Systems, 2019 University of New Mexico - Main Campus

#### Quantum Algorithms With Applications To Simulating Physical Systems, Anirban Ch Narayan Chowdhury

*Physics & Astronomy ETDs*

The simulation of quantum physical systems is expected to be an important application for quantum computers. The work presented in this dissertation aims to improve the resource requirements of quantum computers for solving simulation problems, by providing both novel quantum algorithms and improved implementations of existing ones. I present three main results that cover diverse aspects of simulation including equilibrium physics, the preparation of useful quantum states, and simulations based on classical stochastic processes. The results rely on established quantum algorithms and other recent techniques which I review. My first original contribution is a new quantum algorithm to sample from ...

Stereodynamical Control Of A Quantum Scattering Resonance In Cold Molecular Collisions, 2019 Universidad de Salamanca

#### Stereodynamical Control Of A Quantum Scattering Resonance In Cold Molecular Collisions, Pablo G. Jambrina, James F.E. Croft, Hua Guo, Mark Brouard, Balakrishnan Naduvalath, F. Javier Aoiz

*Chemistry and Biochemistry Faculty Publications*

Cold collisions of light molecules are often dominated by a single partial wave resonance. For the rotational quenching of HD (v=1, j=2) by collisions with ground state para-H2, the process is dominated by a single L=2 partial wave resonance centered around 0.1 K. Here, we show that this resonance can be switched on or off simply by appropriate alignment of the HD rotational angular momentum relative to the initial velocity vector, thereby enabling complete control of the collision outcome.

Topological Nodal Line Semimetals In Graphene Network Structures, 2019 University of Chinese Academy of Sciences

#### Topological Nodal Line Semimetals In Graphene Network Structures, Jian-Tao Wang, Hongming Weng, Chengfeng Chen

*Physics & Astronomy Faculty Publications*

Topological semimetals are a fascinating class of quantum materials that possess extraordinary electronic and transport properties. These materials have attracted great interests in recent years for their fundamental significance and potential device applications. There have been intensive studies suggested that three-dimensional graphene networks support topological semimetals with two types of continuous nodal lines: one is to form closed nodal rings in Brillouin zone and the other ones traversing the whole Brillouin zone to be periodically connected. Carbon has negligible spin-orbit coupling, non-magnetism and great diversity of allotropes, which makes it very promising in realizing topological nodal line semimetals. Here we ...

Optimization Of Information Storage With Quantum Walks, 2019 CUNY Hunter College

#### Optimization Of Information Storage With Quantum Walks, Gui Zhen Lu

*School of Arts & Sciences Theses*

A four-vertex quantum graph was analyzed with the objective of storing the highest ampli- tude of an incoming qubit. The procedure included the use of phase shifters to allow the user to store and release information when he or she chooses. Several parameters, such as the phase shift, location of the phase shifter, the size and shape of the binding graph and initial incoming state were varied independently to optimize the storage capacity of the graph.

Phantoms In Science: Nietzsche's Nonobjectivity On Planck's Quanta, 2019 Bellarmine University

#### Phantoms In Science: Nietzsche's Nonobjectivity On Planck's Quanta, Donald Richard Dickerson Iii

*Undergraduate Theses*

What does Maxwell Planck's concept of phantomness suggest about the epistemological basis of science and how might a Nietzschean critique reveal solution to the weaknesses revealed? With his solution to Kirchoff's equation, Maxwell Planck launched the paradigm of quantum physics. This same solution undermined much of current understandings of science versus pseudoscience. Using Nietzsche's perspectivism and other philosophical critiques, Planck's answer to blackbody radiation is used to highlight the troubles with phantom problems in science and how to try to direct science towards a more holistic and complete scientific approach.

Toward Devices For Exploring Pt-Symmetry In Electronic Transport Of Graphene, 2019 Washington University in St. Louis

#### Toward Devices For Exploring Pt-Symmetry In Electronic Transport Of Graphene, Michael Carovillano

*Senior Honors Papers / Undergraduate Theses*

Parity-time symmetry, or PT -symmetry is the principle that in quantum mechanics a non- Hermitian Hamiltonian is capable of returning real eigenstates and real spectra.Recent research has demonstrated real world observation of PT -symmetry in electronics and optics. We aim to expand the regime of observed PT -symmetry through measurement of the electronic transport of graphene devices. Drawing from analogous experiments, we plan to use balanced ohmic resistance acting as both loss and relative gain to induce the required unbroken PT -symmetry regime. This paper analyzes techniques used in fabrication of such devices as well as the basis of ...

Exploring Quantum Dynamics And Thermodynamics In Superconducting Qubits, 2019 Washington University in St. Louis

#### Exploring Quantum Dynamics And Thermodynamics In Superconducting Qubits, Mahdi Naghiloo

*Arts & Sciences Electronic Theses and Dissertations*

Quantum technology has been rapidly growing due to its potential revolutionary applications. In particular, superconducting qubits provide a strong light-matter interaction as required for quantum computation and in principle can be scaled up to a high level of complexity. However, obtaining the full benet of quantum mechanics in superconducting circuits requires a deep understanding of quantum physics in such systems in all aspects. One of the most crucial aspects is the concept of measurement and the dynamics of the quantum systems under the measurement process. This thesis is intended to be a pedagogical introduction to the concept of quantum measurement ...

Topics In Three-Dimensional Imaging, Source Localization And Super-Resolution, 2019 University of New Mexico

#### Topics In Three-Dimensional Imaging, Source Localization And Super-Resolution, Zhixian Yu

*Physics & Astronomy ETDs*

The realization that twisted light beams with helical phasefronts could carry orbital angular momentum (OAM) that is in excess of the photon's spin angular momentum (SAM) has spawned various important applications. One example is the design of novel imaging systems that achieve three-dimensional (3D) imaging in a single snapshot via the rotation of point spread function (PSF).

Based on a scalar-field analysis, a particular simple version of rotating PSF imagery, which was proposed by my advisor Dr. Prasad, furnishes a practical approach to perform 3D source localization using a spiral phase mask that generates a combination of Bessel vortex ...

Experimental Evidence Supportive Of The Quantum Dna Model, 2019 University of Tennessee Health Science Center

#### Experimental Evidence Supportive Of The Quantum Dna Model, F. Matthew Mihelic

*Faculty Publications*

The DNA molecule can be modeled as a quantum logic processor in which electron spin qubits are held coherently in each nucleotide in a logically and thermodynamically reversible enantiomeric symmetry, and can be coherently conducted along the pi-stacking interactions of aromatic nucleotide bases, while simultaneously being spin-filtered via the helicity of the DNA molecule. Entangled electron pairs can be separated by that spin-filtering, held coherently at biological temperatures in the topologically insulated nucleotide quantum gates, and incorporated into separate DNA strands during DNA replication. Two separate DNA strands that share quantum entangled electrons can be mitotically divided into individual cells ...

Nominalization And Interpretation: A Critique Of Global Nominalization Criteria, 2019 University of Wisconsin-Milwaukee

#### Nominalization And Interpretation: A Critique Of Global Nominalization Criteria, Jason Alen Dewitt

*Theses and Dissertations*

Nominalization is the process which removes abstract objects from our scientific theories. But what makes a proposed nominalization a good or successful one? In the paper “Is It Possible to Nominalize Quantum Mechanics,” Otávio Bueno develops criteria for any successful nominalization. In the present work, I discuss one of these criteria that I call the “interpretation criterion.” It claims that a nominalization of a scientific theory should be neutral with regards to the interpretations of that theory. I argue that the interpretation criterion is problematic, and that it should be replaced with an alternative criterion of nominalization. I first explicate ...

Free Electron Sources And Diffraction In Time, 2019 University of Nebraska-Lincoln

#### Free Electron Sources And Diffraction In Time, Eric R. Jones

*Theses, Dissertations, and Student Research: Department of Physics and Astronomy*

The quantum revolution of the last century advanced synergistically with technology, for example, with control of the temporal and spatial coherence, and the polarization state of light. Indeed, experimental confirmation of the quirks of quantum theory, as originally highlighted by Einstein, Podolsky, and Rosen, through Bohm, and then Bell, have been performed with photons, i.e., electromagnetic wave packets prepared in the same quantum states. Experimental tests of quantum mechanics with matter wave packets have been limited due to challenges in preparing all of the packets with similar quantum states. While great strides have been made for trapped atoms and ...

Unbounded Derivations Of C*-Algebras And The Heisenberg Commutation Relation, 2019 University of Nebraska-Lincoln

#### Unbounded Derivations Of C*-Algebras And The Heisenberg Commutation Relation, Lara M. Ismert

*Dissertations, Theses, and Student Research Papers in Mathematics*

This dissertation investigates the properties of unbounded derivations on C*-algebras, namely the density of their analytic vectors and a property we refer to as "kernel stabilization." We focus on a weakly-defined derivation δ_{D} which formalizes commutators involving unbounded self-adjoint operators on a Hilbert space. These commutators naturally arise in quantum mechanics, as we briefly describe in the introduction.

A first application of kernel stabilization for δ_{D} shows that a large class of abstract derivations on unbounded C*-algebras, defined by O. Bratteli and D. Robinson, also have kernel stabilization. A second application of kernel stabilization provides a ...

A Qubit Algorithm For Simulating The Nonlinear Schroedinger Equation, 2019 William & Mary

#### A Qubit Algorithm For Simulating The Nonlinear Schroedinger Equation, Connor Simpson

*Undergraduate Honors Theses*

Recent work in mathematical physics and nonlinear optics has shown that Hamiltonians that are non-Hermitian but still symmetric under parity and time reversal can describe eigenstates of a system with real eigenvalues. Other research has also showed that the nonlinear Schrodinger equation can be generalized to describe PT-symmetric systems, which generates novel solutions not described by its Hermitian equivalent. The Hermitian form of the nonlinear Schroedinger equation can also be extended to describe a particular case of the general PT-symmetric NLS, suggesting a connection between the two. I attempted to generate a unitary operator that will be useful for unitary ...

Topological Insulating States In Photonics And Acoustics, 2019 The Graduate Center, City University of New York

#### Topological Insulating States In Photonics And Acoustics, Xiang Ni

*Dissertations, Theses, and Capstone Projects*

Recent surge of interest in topological insulators, insulating in their interior but conducting at the surfaces or interfaces of different domains, has led to the discovery of a variety of new topological states, and their topological invariants are characterized by numerous approaches in the category of topological band theory. The common features shared by topological insulators include, the topological phase transition occurs if the bulk bandgap is formed due to the symmetries reduction, the topological invariants exist characterizing the global properties of the material and inherently robust to disorder and continuous perturbations irrespective of the local details. Most importantly, these ...

Implementing A Self-Corrected Chemical Potential Scheme In Determinant Quantum Monte Carlo Simulations, 2019 University of Tennessee, Knoxville

#### Implementing A Self-Corrected Chemical Potential Scheme In Determinant Quantum Monte Carlo Simulations, Kevin Gordon Kleiner

*Chancellor’s Honors Program Projects*

No abstract provided.

The Nature Of The Heisenberg-Von Neumann Cut: Enhanced Orthodox Interpretation Of Quantum Mechanics, 2019 California Institute for Integral Studies

#### The Nature Of The Heisenberg-Von Neumann Cut: Enhanced Orthodox Interpretation Of Quantum Mechanics, Ashok Narasimhan, Deepak Chopra, Menas Kafatos

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

We examine the issue of the Heisenberg-von Neumann cut in light of recent interpretations of quantum eraser experiments which indicate the possibility of a universal Observer outside space-time at an information level of existence. The delayed-choice aspects of observation, measurement, the role of the observer, and information in the quantum framework of the universe are discussed. While traditional double-slit experiments are usually interpreted as indicating that the collapse of the wave function involves choices by an individual observer in space-time, the extension to quantum eraser experiments brings in some additional subtle aspects relating to the role of observation and what ...

Roadmap On Superoscillations, 2019 University of Bristol

#### Roadmap On Superoscillations, Michael Berry, Nicolay Zheludev, Yakir Aharonov, Fabrizio Colombo, Irene Sabadini, Daniele C. Struppa, Jeff Tollaksen, Edward T. F. Rogers, Fei Qin, Minghui Hong, Xiangang Luo, Roei Remez, Ady Arie, Jörg B. Götte, Mark R. Dennis, Alex M. H. Wong, George V. Eleftheriades, Yaniv Eliezer, Alon Bahabad, Gang Chen, Zhongquan Wen, Gaofeng Liang, Chenglong Hao, C-W Qiu, Achim Kempf, Eytan Katzav, Moshe Schwartz

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

Superoscillations are band-limited functions with the counterintuitive property that they can vary arbitrarily faster than their fastest Fourier component, over arbitrarily long intervals. Modern studies originated in quantum theory, but there were anticipations in radar and optics. The mathematical understanding—still being explored—recognises that functions are extremely small where they superoscillate; this has implications for information theory. Applications to optical vortices, sub-wavelength microscopy and related areas of nanoscience are now moving from the theoretical and the demonstrative to the practical. This Roadmap surveys all these areas, providing background, current research, and anticipating future developments.

Realization Of Tensor Product And Of Tensor Factorization Of Rational Functions, 2019 Chapman University

#### Realization Of Tensor Product And Of Tensor Factorization Of Rational Functions, Daniel Alpay, Izchak Lewkowicz

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

We study the state space realization of a tensor product of a pair of rational functions. At the expense of “inflating” the dimensions, we recover the classical expressions for realization of a regular product of rational functions. Under an additional assumption that the limit at infinity of a given rational function exists and is equal to identity, we introduce an explicit formula for a *tensor factorization* of this function.

Improving The Readout Of Semiconducting Qubits, 2019 University of New Mexico

#### Improving The Readout Of Semiconducting Qubits, Matthew Jon Curry

*Physics & Astronomy ETDs*

Semiconducting qubits are a promising platform for quantum computers. In particular, silicon spin qubits have made a number of advancements recently including long coherence times, high-fidelity single-qubit gates, two-qubit gates, and high-fidelity readout. However, all operations likely require improvement in fidelity and speed, if possible, to realize a quantum computer.

Readout fidelity and speed, in general, are limited by circuit challenges centered on extracting low signal from a device in a dilution refrigerator connected to room temperature amplifiers by long coaxial cables with relatively high capacitance. Readout fidelity specifically is limited by the time it takes to reliably distinguish qubit ...

Testing Quantum Coherence In Stochastic Electrodynamics With Squeezed Schrödinger Cat States, 2019 Texas A & M University - College Station

#### Testing Quantum Coherence In Stochastic Electrodynamics With Squeezed Schrödinger Cat States, Wayne Cheng-Wei Huang, Herman Batelaan

*Faculty Publications, Department of Physics and Astronomy*

The interference pattern in electron double-slit diffraction is a hallmark of quantum mechanics. A long-standing question for stochastic electrodynamics (SED) is whether or not it is capable of reproducing such effects, as interference is a manifestation of quantum coherence. In this study, we used excited harmonic oscillators to directly test this quantum feature in SED. We used two counter-propagating dichromatic laser pulses to promote a ground-state harmonic oscillator to a squeezed Schrödinger cat state. Upon recombination of the two well-separated wavepackets, an interference pattern emerges in the quantum probability distribution but is absent in the SED probability distribution. We thus ...