Data Collection And Analysis At The Atlas Detector, 2017 Yale University

#### Data Collection And Analysis At The Atlas Detector, Savannah Thais

*Yale Day of Data*

No abstract provided.

Rapid Estimation Of Drifting Parameters In Continuously Measured Quantum Systems, 2017 University of Rochester

#### Rapid Estimation Of Drifting Parameters In Continuously Measured Quantum Systems, Luis Cortez, Areeya Chantasri, Luis Pedro García-Pintos, Justin Dressel, Andrew N. Jordan

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

We investigate the determination of a Hamiltonian parameter in a quantum system undergoing continuous measurement. We demonstrate a computationally rapid method to estimate an unknown and possibly timedependent parameter, where we maximize the likelihood of the observed stochastic readout. By dealing directly with the raw measurement record rather than the quantum-state trajectories, the estimation can be performed while the data are being acquired, permitting continuous tracking of the parameter during slow drifts in real time. Furthermore, we incorporate realistic nonidealities, such as decoherence processes and measurement inefficiency. As an example, we focus on estimating the value of the Rabi frequency ...

Experimental Demonstration Of Direct Path State Characterization By Strongly Measuring Weak Values In A Matter-Wave Interferometer, 2017 AtomInstitut

#### Experimental Demonstration Of Direct Path State Characterization By Strongly Measuring Weak Values In A Matter-Wave Interferometer, Tobias Denkmayr, Hermann Geppert, Hartmut Lemmel, Mordecai Waegell, Justin Dressel, Yuji Hasegawa, Stephan Sponar

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

A method was recently proposed and experimentally realized for characterizing a quantum state by directly measuring its complex probability amplitudes in a particular basis using so-called weak values. Recently, Vallone and Dequal [Phys. Rev. Lett. 116, 040502 (2016)] showed theoretically that weak measurements are not a necessary condition to determine the weak value. Here, we report a measurement scheme used in a matter-wave interferometric experiment in which the neutron path system’s quantum state was characterized via direct measurements, using both strong and weak interactions. Experimental evidence is given that strong interactions outperform weak ones for tomographic accuracy. Our results ...

Tunneling Assisted Forbidden Transitions In The Single Molecule Magnet Ni4, 2017 University of Massachusetts - Amherst

#### Tunneling Assisted Forbidden Transitions In The Single Molecule Magnet Ni4, Yiming Chen

*Doctoral Dissertations May 2014 - current*

This dissertation presents work in exploring novel quantum phenomena in singlemolecule magnets (SMMs) and superconducting circuits. The degree of the freedom studied is the magnetic moment of a single molecule and the flux quantum trapped in a superconducting ring. These phenomena provide us with new insights into some basic questions of physics and may also find their application in quantum computing.

The molecule we studied is Ni4 ([Ni4(hmp)(dmp)Cl]4) which can be treated as a spin-4 magnet. The large magnetic anisotropy of the molecule leads to bistability of the magnetic moment at low temperatures, with spin-up and ...

Probing Quantumness With Joint Continuous Measurements Of Non-Commuting Observables, 2016 Chapman University

#### Probing Quantumness With Joint Continuous Measurements Of Non-Commuting Observables, Luis Pedro García-Pintos, Justin Dressel

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

We analyze the continuous measurement of two noncommuting observables for a qubit, and investigate whether the simultaneously observed noisy signals are consistent with the evolution of an equivalent classical system. Following the approach outlined by Leggett and Garg, we show that the readouts violate macrorealistic inequalities for arbitrarily short temporal correlations. Moreover, the derived inequalities are manifestly violated even in the absence of Hamiltonian evolution, unlike for Leggett-Garg inequalities that use a single continuous measurement. Such a violation should indicate the failure of at least one postulate of macrorealism: either physical quantities do not have well-defined values at all times ...

Linear Feedback Stabilization For A Continuously Monitored Qubit, 2016 Chapman University

#### Linear Feedback Stabilization For A Continuously Monitored Qubit, Taylor Lee Patti, A. Chantasri, Justin Dressel, A. N. Jordan

*Student Research Day Abstracts and Posters*

In quantum mechanics, standard or strong measurement approaches generally result in the collapse of an ensemble of wavefunctions into a stochastic mixture of eigenstates. On the other hand, continuous or weak measurements have the propensity to dynamically control the evolution of quantum states over time, guiding the trajectory of the state into non-trivial superpositions and maintaining state purity. This kind of measurement-induced state steering is of great theoretical and experimental interest for the harnessing of quantum bits or "qubits", which are the fundamental unit of the emerging quantum computer. We explore continuous measurement-based quantum state stabilization through linear feedback control ...

Properties Of The Schrödinger Theory Of Electrons In Electromagnetic Fields, 2016 CUNY Graduate Center and CUNY Brooklyn College

#### Properties Of The Schrödinger Theory Of Electrons In Electromagnetic Fields, Viraht Sahni, Xiao-Yin Pan

*Publications and Research*

The Schrödinger theory of electrons in an external electromagnetic field can be described from the perspective of the individual electron via the ‘Quantal Newtonian’ laws (or differential virial theorems). These laws are in terms of ‘classical’ fields whose sources are quantal expectations of Hermitian operators taken with respect to the wave function. The laws reveal the following physics: (a) In addition to the external field, each electron experiences an internal field whose components are representative of a specific property of the system such as the correlations due to the Pauli exclusion principle and Coulomb repulsion, the electron density, kinetic effects ...

Resonant Light Scattering From Semiconductor Quantum Dots, 2016 University of South Florida

#### Resonant Light Scattering From Semiconductor Quantum Dots, Kumarasiri Konthasinghe

*Graduate Theses and Dissertations*

In this work, resonant laser spectroscopy has been utilized in two major projects --resonance fluorescence measurements in solid-state quantum-confined nanostructures and laser-induced fluorescence measurements in gases. The first project focuses on studying resonant light-matter interactions in semiconductor quantum dots "artificial atoms" with potential applications in quantum information science. Of primary interest is the understanding of fundamental processes and how they are affected by the solid-state matrix. Unlike atoms, quantum dots are susceptible to a variety of environmental influences such as phonon scattering and spectral diffusion. These interactions alter the desired properties of the scattered light and hinder uses in certain ...

Art As A Tool In Quantum Mechanics, 2016 Oglethopre University

#### Art As A Tool In Quantum Mechanics, Zachary Vealey

*Oglethorpe Journal of Undergraduate Research*

Revolutions in scientific thought often have substantial societal consequences, however, cultural assimilation of the new idea is contingent on a widespread understanding. Historically recent developments in modern physics, such as quantum mechanics and general relativity, suffer from their notoriously perceived difficulty, thus hindering cultural assimilation. To address this issue, art can serve as a useful complement to a student studying quantum mechanics - especially through its interpretation of delocalized electron density. A cross-disciplinary approach affords a greater diversity in participation and consequently results in a broader scientific outreach.

Some 2-Categorical Aspects In Physics, 2016 The Graduate Center, City University of New York

#### Some 2-Categorical Aspects In Physics, Arthur Parzygnat

*All Graduate Works by Year: Dissertations, Theses, and Capstone Projects*

2-categories provide a useful transition point between ordinary category theory and infinity-category theory where one can perform concrete computations for applications in physics and at the same time provide rigorous formalism for mathematical structures appearing in physics. We survey three such broad instances. First, we describe two-dimensional algebra as a means of constructing non-abelian parallel transport along surfaces which can be used to describe strings charged under non-abelian gauge groups in string theory. Second, we formalize the notion of convex and cone categories, provide a preliminary categorical definition of entropy, and exhibit several examples. Thirdly, we provide a universal description ...

Prioritizing Investment In Residential Energy Efficiency And Renewable Energy: A Case Study For The U.S. Midwest, 2016 University of Dayton

#### Prioritizing Investment In Residential Energy Efficiency And Renewable Energy: A Case Study For The U.S. Midwest, Robert J. Brecha, Austin Mitchell, Kevin P. Hallinan, J. Kelly Kissock

*J. Kissock*

Residential building energy use is an important contributor to greenhouse gas emissions and in the United States represents about 20% of total energy consumption. A number of previous macro-scale studies of residential energy consumption and energy-efficiency improvements are mainly concerned with national or international aggregate potential savings. In this paper we look into the details of how a collection of specific homes in one region might reduce energy consumption and carbon emissions, with particular attention given to some practical limits to what can be achieved by upgrading the existing residential building stock. Using a simple model of residential, single-family home ...

Dicke’S Superradiance In Astrophysics, 2016 The University of Western Ontario

#### Dicke’S Superradiance In Astrophysics, Fereshteh Rajabi

*Electronic Thesis and Dissertation Repository*

It is generally assumed that in the interstellar medium much of the emission emanating from atomic and molecular transitions within a radiating gas happen independently for each atom or molecule, but as was pointed out by R. H. Dicke in a seminal paper several decades ago this assumption does not apply in all conditions. As will be discussed in this thesis, and following Dicke’s original analysis, closely packed atoms/molecules can interact with their common electromagnetic field and radiate coherently through an effect he named superradiance. Superradiance is a cooperative quantum mechanical phenomenon characterized by high intensity, spatially compact ...

Electron Correlations In Local Effective Potential Theory, 2016 CUNY Graduate Center and CUNY Brooklyn College

#### Electron Correlations In Local Effective Potential Theory, Viraht Sahni, Xiao-Yin Pan, Tao Yang

*Publications and Research*

Local effective potential theory, both stationary-state and time-dependent, constitutes the mapping from a system of electrons in an external field to one of the noninteracting fermions possessing the same basic variable such as the density, thereby enabling the determination of the energy and other properties of the electronic system. This paper is a description via Quantal Density Functional Theory (QDFT) of the electron correlations that must be accounted for in such a mapping. It is proved through QDFT that independent of the form of external field, (a) it is possible to map to a model system possessing all the basic ...

Photonicstd-2d: Modeling Light Scattering In Periodic Multilayer Photonic Structures, 2016 North Carolina State University at Raleigh

#### Photonicstd-2d: Modeling Light Scattering In Periodic Multilayer Photonic Structures, Alexey Bondarev, Shaimaa Azzam, Zhaxylyk Kudyshev, Alexander V. Kildishev

*The Summer Undergraduate Research Fellowship (SURF) Symposium*

Efficient modeling of electromagnetic processes in optical and plasmonic metamaterials is important for enabling new and exciting ways to manipulate light for advanced applications. In this work, we put together a tool for numerical simulation of propagation of normally incident light through a nanostructured multilayer composite material. The user builds a unit cell of a given material layer-by-layer starting from a substrate up to a superstrate, splitting each layer further into segments. The segments are defined by width and material -- dielectric, metal or active medium. Simulations are performed with the finite difference time domain (FDTD) method. A database of common ...

Measuring A Transmon Qubit In Circuit Qed: Dressed Squeezed States, 2016 University of California, Riverside

#### Measuring A Transmon Qubit In Circuit Qed: Dressed Squeezed States, Mostafa Khezri, Eric Mlinar, Justin Dressel, A. N. Korotkov

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

Using circuit QED, we consider the measurement of a superconducting transmon qubit via a coupled microwave resonator. For ideally dispersive coupling, ringing up the resonator produces coherent states with frequencies matched to transmon energy states. Realistic coupling is not ideally dispersive, however, so transmon-resonator energy levels hybridize into joint eigenstate ladders of the Jaynes–Cummings type. Previous work has shown that ringing up the resonator approximately respects this ladder structure to produce a coherent state in the eigenbasis (a dressed coherent state). We numerically investigate the validity of this coherent-state approximation to find two primary deviations. First, resonator ring-up leaks ...

Investigation Of Carbon Nanomaterials Embedded In A Cementitious Matrix, 2016 Western Kentucky University

#### Investigation Of Carbon Nanomaterials Embedded In A Cementitious Matrix, Clarissa A. Roe

*Masters Theses & Specialist Projects*

The objective of this thesis was to investigate whether the addition of carbon nanofibers had an effect on the splitting tensile strength of Hydro-Stone gypsum concrete. The carbon nanofibers used were single-walled carbon nanotubes (SWNT), buckminsterfullerene (C60), and graphene oxide (GO). Evidence of the nanofibers interacting with gypsum crystals in a connective manner was identified in both 1 mm thick concrete discs and concrete columns possessing a height of 2 in and a diameter of 1 in. Before imaging, the columns were subjected to a splitting tensile strength test. The results illustrate that while there is a general decrease in ...

Prioritizing Investment In Residential Energy Efficiency And Renewable Energy: A Case Study For The U.S. Midwest, 2016 University of Dayton

#### Prioritizing Investment In Residential Energy Efficiency And Renewable Energy: A Case Study For The U.S. Midwest, Robert J. Brecha, Austin Mitchell, Kevin P. Hallinan, J. Kelly Kissock

*Kevin Hallinan*

Residential building energy use is an important contributor to greenhouse gas emissions and in the United States represents about 20% of total energy consumption. A number of previous macro-scale studies of residential energy consumption and energy-efficiency improvements are mainly concerned with national or international aggregate potential savings. In this paper we look into the details of how a collection of specific homes in one region might reduce energy consumption and carbon emissions, with particular attention given to some practical limits to what can be achieved by upgrading the existing residential building stock. Using a simple model of residential, single-family home ...

Theoretical Analysis Of Single Molecule Spectroscopy Lineshapes Of Conjugated Polymers, 2016 Graduate Center, City University of New York

#### Theoretical Analysis Of Single Molecule Spectroscopy Lineshapes Of Conjugated Polymers, Murali Devi

*All Graduate Works by Year: Dissertations, Theses, and Capstone Projects*

Conjugated Polymers(CPs) exhibit a wide range of highly tunable optical properties. Quantitative and detailed understanding of the nature of excitons responsible for such a rich optical behavior has significant implications for better utilization of CPs for more efficient plastic solar cells and other novel optoelectronic devices. In general, samples of CPs are plagued with substantial inhomogeneous broadening due to various sources of disorder. Single molecule emission spectroscopy (SMES) offers a unique opportunity to investigate the energetics and dynamics of excitons and their interactions with phonon modes. The major subject of the present thesis is to analyze and understand room ...

Elements Of The Mathematical Formulation Of Quantum Mechanics, 2016 Washington University in Saint Louis

#### Elements Of The Mathematical Formulation Of Quantum Mechanics, Keunjae Go

*Senior Honors Papers / Undergraduate Theses*

In this paper, we will explore some of the basic elements of the mathematical formulation of quantum mechanics. In the first section, I will list the motivations for introducing a probability model that is quite different from that of the classical probability theory, but still shares quite a few significant commonalities. Later in the paper, I will discuss the quantum probability theory in detail, while paying a brief attention to some of the axioms (by Birkhoff and von Neumann) that illustrate both the commonalities and differences between classical mechanics and quantum mechanics. This paper will end with a presentation of ...

Totally Positive Density Matrices And Linear Preservers, 2016 University of Guelph

#### Totally Positive Density Matrices And Linear Preservers, David Kribs, Jeremy Levick, Rajesh Pereira

*Electronic Journal of Linear Algebra*

The intersection between the set of totally nonnegative matrices, which are of interest in many areas of matrix theory and its applications, and the set of density matrices, which provide the mathematical description of quantum states, are investigated. The single qubit case is characterized, and several equivalent conditions for a quantum channel to preserve the set in that case are given. Higher dimensional cases are also discussed.