Optimization Of An Injection Locked Laser System For Cold Neutral Atom Traps,
2019
California Polytechnic State University, San Luis Obispo
Optimization Of An Injection Locked Laser System For Cold Neutral Atom Traps, Elliot M. Lehman
Physics
Many types of quantum systems are being explored for use in quantum computers. One type of quantum system that shows promise for quantum computing is trapped neutral atoms. They have long coherence times, since they have multiple stable ground states and have minimal coupling with other atoms and their environment, and they can be trapped in arrays, making them individu- ally addressable. Once trapped, they can be initialized and operated on using laser pulses. This experiment utilizes a pinhole diffraction pattern, which can trap atoms in both bright and dark areas. To maximize trap strength, an injection-locked laser amplification system …
Control Of Light-Matter Interactions Via Nanostructured Photonic Materials,
2019
CUNY Graduate Center
Control Of Light-Matter Interactions Via Nanostructured Photonic Materials, Nicholas Proscia
Dissertations, Theses, and Capstone Projects
The thesis here investigates the manipulation of light-matter interactions via nanoscale engineering of material systems. When material systems are structured on the nanoscale, their optical responses can be dramatically altered. In this thesis, this is done in two primary ways: One method is by changing the geometry of nanostructures to induce a resonant behavior with incident electromagnetic field of optical wavelengths. This allows field enhancement in highly localized areas to strengthen exotic light-matter interactions that would otherwise be too weak to measure or for practical use. In this regard, the work presented here studies a voltage produced in a metal …
Out-Of-Time-Ordered-Correlator Quasiprobabilities Robustly Witness Scrambling,
2019
Chapman University
Out-Of-Time-Ordered-Correlator Quasiprobabilities Robustly Witness Scrambling, José Raúl González Alonso, Nicole Yunger Halpern, Justin Dressel
Mathematics, Physics, and Computer Science Faculty Articles and Research
Out-of-time-ordered correlators (OTOCs) have received considerable recent attention as qualitative witnesses of information scrambling in many-body quantum systems. Theoretical discussions of OTOCs typically focus on closed systems, raising the question of their suitability as scrambling witnesses in realistic open systems. We demonstrate empirically that the nonclassical negativity of the quasiprobability distribution (QPD) behind the OTOC is a more sensitive witness for scrambling than the OTOC itself. Nonclassical features of the QPD evolve with timescales that are robust with respect to decoherence and are immune to false positives caused by decoherence. To reach this conclusion, we numerically simulate spinchain dynamics and …
Peculiar Optical Properties Of Bilayer Silicene Under The Influence Of External Electric And Magnetic Fields,
2019
Academia Sinica
Peculiar Optical Properties Of Bilayer Silicene Under The Influence Of External Electric And Magnetic Fields, Thi-Nga Do, Godfrey Gumbs, Po-Hsin Shih, Danhong Huang, Chih-Wei Chiu, Chia-Yun Chen, Ming-Fa Lin
Publications and Research
We conduct a comprehensive investigation of the effect of an applied electric field on the optical and magneto-optical absorption spectra for AB-bt (bottom-top) bilayer silicene. The generalized tightbinding model in conjunction with the Kubo formula is efficiently employed in the numerical calculations. The electronic and optical properties are greatly diversified by the buckled lattice structure, stacking configuration, intralayer and interlayer hopping interactions, spin-orbital couplings, as well as the electric and magnetic fields (Ez ˆz & Bz ˆz ). An electric field induces spin-split electronic states, a semiconductor-metal phase transitions and the Dirac cone formations in different valleys, leading to the …
Comparisons Of Performance Between Quantum And Classical Machine Learning,
2019
Southern Methodist University
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 …
Modification Of Counterfactual Communication Protocols That Eliminates Weak Particle Traces,
2019
Chapman University
Modification Of Counterfactual Communication Protocols That Eliminates Weak Particle Traces, Yakir Aharonov, Lev Vaidman
Mathematics, Physics, and Computer Science Faculty Articles and Research
The possibility to communicate between spatially separated regions, without even a single photon passing between the two parties, is an amazing quantum phenomenon. The possibility of transmitting one value of a bit in such a way, the interaction-free measurement, has been known for quarter of a century. The protocols of full communication, including transmitting unknown quantum states, were proposed only a few years ago, but it was shown that in all these protocols the particle was leaving a weak trace in the transmission channel, the trace being larger than the trace left by a single particle passing through the channel. …
Hybrid Excitations In Organic-Semiconductor Materials,
2019
Marshall University
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 …
Quantum Isometry Group Of Deformation: A Counterexample,
2019
Indian Statistical Institute, Kolkata
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.
Quantized Circulation In Racetrack Atomtronic Circuits At Non-Zero Temperature,
2019
Georgia Southern University
Quantized Circulation In Racetrack Atomtronic Circuits At Non-Zero Temperature, Benjamin R. Eller
College of Graduate Studies: Theses & Dissertations
We extend previous theoretical investigations of the creation of quantized circulation states by stirring Bose-Einstein condensates (BEC) confined in ``racetrack" potentials. The previous study, {\em Producing Smooth Flow in Atom Circuits by Stirring}, used the Gross-Pitaevskii equation (GPE), which is valid at $T=0$ K. Here we use a non-zero temperature model based on the Zaremba, Nikuni, Griffin (ZNG) theory to simulate stirring racetrack BECs. The two main goals of this thesis are 1) to understand the effects of temperature on the production of circulation and 2) to understand the mechanism by which the circulation is excited. We find that it …
Theoretical Studies Of The Structure And Stability Of Metal Chalcogenide Crntem (1≤N≤6, 1≤M≤8) Clusters,
2019
Virginia Commonwealth University
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, CrnTem 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 …
An Introduction To Supersymmetric Quantum Mechanics,
2019
Virginia Commonwealth University
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.
Electron Transport In One And Two Dimensional Materials,
2019
University at Albany, State University of New York
Electron Transport In One And Two Dimensional Materials, Samuel William Lagasse
Legacy Theses & Dissertations (2009 - 2024)
This dissertation presents theoretical and experimental studies in carbon nanotubes (CNTs), graphene, and van der Waals heterostructures. The first half of the dissertation focuses on cutting edge tight-binding-based quantum transport models which are used to study proton irradiation-induced single-event effects in carbon nanotubes [1], total ionizing dose effects in graphene [2], quantum hall effect in graded graphene p-n junctions [3], and ballistic electron focusing in graphene p-n junctions [4]. In each study, tight-binding models are developed, with heavy emphasis on tying to experimental data. Once benchmarked against experiment, properties of each system which are difficult to access in the laboratory, …
Why Physical Understanding Should Precede The Mathematical Formalism—Conditional Quantum Probabilities As A Case-Study,
2019
Chapman University
Why Physical Understanding Should Precede The Mathematical Formalism—Conditional Quantum Probabilities As A Case-Study, Yakir Aharonov, Eliahu Cohen, David H. Oaknin
Mathematics, Physics, and Computer Science Faculty Articles and Research
Conditional probabilities in quantum systems which have both initial and final boundary conditions are commonly evaluated using the Aharonov–Bergmann–Lebowitz rule. In this short note, we present a seemingly disturbing paradox that appears when applying the rule to systems with slightly broken degeneracies. In these cases, we encounter a singular limit—the probability “jumps” when going from perfect degeneracy to negligibly broken one. We trace the origin of the paradox and solve it from both traditional and modern perspectives in order to highlight the physics behind it: the necessity to take into account the finite resolution of the measuring device. As a …
Environmental Effects On Nonlocal Correlations,
2019
Indian Statistical Institute, Kolkata
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. …
Reconstruction Of Top Quark Pair Dilepton Decays In Electron-Positron Collisions,
2019
CUNY Graduate Center
Reconstruction Of Top Quark Pair Dilepton Decays In Electron-Positron Collisions, Helenka Casler, Matthew Manganel, Miguel C. N. Fiolhais, Andrea Ferroglia, António Onofre
Publications and Research
A new algorithm is presented to perform the full kinematic reconstruction of top quark pair events produced at future electron-positron colliders in the case of dilepton decays of the W bosons to electrons or muons. The momentum components of the undetected neutrino and antineutrino in the event are reconstructed by employing several kinematic conditions comprising a nonlinear system of six equations. This system is solved numerically using two independent methods, and the selection of the best candidate real solution for each event is determined by a likelihood discriminant. Results are presented for several reconstructed kinematic properties of the W± …
Working Group 6 Summary: Spin And 3d Structure,
2019
Brookhaven National Laboratory
Working Group 6 Summary: Spin And 3d Structure, Oleg Eyser, Bakur Parsamyan, Ted Rogers
Physics Faculty Publications
The spin and 3D structure session of the DIS2019 conference focused on recent efforts to understand nucleon structure using collinear factorization theorems, transverse momentum dependent correlation functions (TMDs), generalized parton distribution (GPDs) and similar objects. A large amount of progress in both theoretical and experimental directions was reported. We summarize some of the highlights here.
Polarized Hyperon Production In Single-Inclusive Electron Positron Annihilation At Next-To-Leading Order,
2019
Old Dominion University
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 …
Three-Particle Systems With Resonant Subprocesses In A Finite Volume,
2019
Old Dominion University
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 …
Question 1: Goosed; Question 2: Buying Groceries,
2019
Old Dominion University
Question 1: Goosed; Question 2: Buying Groceries, Larry Weinstein
Physics Faculty Publications
The article presents two questions related to fermi which include injury of a celebrity colliding with a goose in the Apollo's Chariot roller coaster; and cost to purchase the contents of local large supermarket.
Quark-Mass Dependence Of Elastic Πk Scattering From Qcd,
2019
Old Dominion University
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 …
