Open Access. Powered by Scholars. Published by Universities.®

Quantum Physics Commons

Open Access. Powered by Scholars. Published by Universities.®

619 Full-Text Articles 864 Authors 91869 Downloads 79 Institutions

All Articles in Quantum Physics

Faceted Search

619 full-text articles. Page 1 of 22.

Optimizing An Electron's Path To Ionization Using A Genetic Algorithm, Jason Bennett, Kevin Choice 2017 Ursinus College

Optimizing An Electron's Path To Ionization Using A Genetic Algorithm, Jason Bennett, Kevin Choice

Physics and Astronomy Summer Fellows

A Rydberg atom is an atom with a highly excited and weakly bound valence electron. A widespread method of studying quantum mechanics with Rydberg atoms is to ionize the electron and measure its arrival time. We use a Genetic Algorithm (GA) to control the electron's path to ionization. The Rydberg electron's energy levels are strongly shifted by the presence of an electric field. The energy levels shift and curve, but never cross. At an avoided crossing the electron can jump from one level to the next. By engineering the electric field's time dependence, we thereby control the ...


The Mathematical Structure Of Arrangement Channel Quantum Mechanics, James W. Evans 2017 Iowa State University

The Mathematical Structure Of Arrangement Channel Quantum Mechanics, James W. Evans

James W. Evans

A non-Hermitian matrix Hamiltonian H appears in the wavefunction form of a variety of many-body scattering theories. This operator acts on an arrangement channel Banach or Hilbert space 1(;' = Ell ncr where ,r is the N-particle Hilbert space and a are certain arrangement channels. Various aspects of the spectral and semigroup theory for H are considered. The normalizable and weak (wavelike) eigenvectors ofH are naturally characterized as either physical or spurious. Typically H is scalar spectral and "equivalent" to H on an H-invariant subspace of physical solutions. If the eigenvectors form a basis, by constructing a suitable biorthogonal system, we ...


Quantum Optical Interferometry And Quantum State Engineering, Richard J. Birrittella Jr 2017 The Graduate Center, City University of New York

Quantum Optical Interferometry And Quantum State Engineering, Richard J. Birrittella Jr

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

We highlight some of our research done in the fields of quantum optical interferometry and quantum state engineering. We discuss the body of work for which our research is predicated, as well as discuss some of the fundamental tenants of the theory of phase estimation. We do this in the context of quantum optical interferometry where our primary interest lies in the calculation of the quantum Fisher information as it has been shown that the minimum phase uncertainty obtained, the quantum Cramer-Rao bound, is saturated by parity-based detection methods. We go on to show that the phase uncertainty one obtains ...


On-Sight Shifting At The Cryogenic Underground Observatory For Rare Events, Aaron C. Wong 2017 California Polytechnic State University, San Luis Obispo

On-Sight Shifting At The Cryogenic Underground Observatory For Rare Events, Aaron C. Wong

Physics

During the summer of 2016, four Cal Poly students traveled to Assergi, Italy to contribute to the CUORE collaboration which is in search of a rare process called neutrinoless double beta decay. If detected, neutrinoless double beta decay will make break throughs in particle and nuclear physics, and will be the first observation of lepton number violation. The Cal Poly students provided on-sight shifting support during the installation phase of the project. This is a breakdown of the physics behind CUORE and Cal Poly's contribution.


The Iterative Method For Quantum Double-Well And Symmetry-Breaking Potentials, Nada Alsufyani 2017 Clark Atlanta University

The Iterative Method For Quantum Double-Well And Symmetry-Breaking Potentials, Nada Alsufyani

Electronic Theses & Dissertations Collection for Atlanta University & Clark Atlanta University

Numerical solutions of quantum mechanical problems have witnessed tremendous advances over the past years. In this thesis, we develop an iterative approach to problems of double-well potentials and their variants with parity-time-reversal symmetry- breaking perturbations. We show that the method provides an efficient scheme for obtaining accurate energies and wave functions. We discuss in this thesis potential applications to a variety of related topics such as phase transitions, symmetry breaking, and external field-induced effects.


Orthogonal Representations, Projective Rank, And Fractional Minimum Positive Semidefinite Rank: Connections And New Directions, Leslie Hogben, Kevin F. Palmowski, David E. Roberson, Simone Severini 2017 Iowa State University

Orthogonal Representations, Projective Rank, And Fractional Minimum Positive Semidefinite Rank: Connections And New Directions, Leslie Hogben, Kevin F. Palmowski, David E. Roberson, Simone Severini

Electronic Journal of Linear Algebra

Fractional minimum positive semidefinite rank is defined from r-fold faithful orthogonal representations and it is shown that the projective rank of any graph equals the fractional minimum positive semidefinite rank of its complement. An r-fold version of the traditional definition of minimum positive semidefinite rank of a graph using Hermitian matrices that fit the graph is also presented. This paper also introduces r-fold orthogonal representations of graphs and formalizes the understanding of projective rank as fractional orthogonal rank. Connections of these concepts to quantum theory, including Tsirelson's problem, are discussed.


Studies In Mesoscopics And Quantum Microscopies, Zhenghao Ding, Gabriel C. Spalding 2017 Illinois Wesleyan University

Studies In Mesoscopics And Quantum Microscopies, Zhenghao Ding, Gabriel C. Spalding

Honors Projects

This thesis begins with a foundational section on quantum optics. The single-photon detectors used in the first chapter were obtained through the Advanced Laboratory Physics Association (ALPhA), which brokered reduced cost for educational use, and the aim of the single-photon work presented in Chapter 1 is to develop modules for use in Illinois Wesleyan's instructional labs beyond the first year of university. Along with the American Association of Physics Teachers, ALPhA encourages capstone-level work, such as Chapter 1 of this honors thesis, which is explicitly designed to play the role of passing on, to a next generation of physics ...


Holographic Non-Perturbative Thermodynamic Systems, Michael C. Kopreski 2017 College of William and Mary

Holographic Non-Perturbative Thermodynamic Systems, Michael C. Kopreski

Undergraduate Honors Theses

The anti-de Sitter/conformal field theory (AdS/CFT) correspondence conjectures a duality between field theories and higher dimensional theories of gravitation. Recent results describing thermodynamic systems in the AdS/CFT context include an exact description of the efficiency of black hole heat engines, suggesting questions regarding the nature of heat engines within this formulation and the extent to which thermodynamic principles may be applied. We verify the Clausius statement and the maximum efficiency of the Carnot engine, and show that these follow from the thermodynamic definitions of the heat engine.

In a related scope, we propose that, given the Ryu-Takayanagi ...


Key Encryption Through Quantum Optics, Madison Durrance, Zach Galberd, Abbey Savage, Tristan Cabrera, Josh Hoffman 2017 Georgia College and State University

Key Encryption Through Quantum Optics, Madison Durrance, Zach Galberd, Abbey Savage, Tristan Cabrera, Josh Hoffman

Georgia College Student Research Events

Cryptography has been around since the dawn of human civilization to send private messages for commercial, military, and political purposes. Some of the most important ciphers are the Vigenère cipher, the enigma, and the more modern RSA. Because of the development of the internet, private encryption has also become increasingly more important. The weakest link of encryption is the key creation and key distribution. A key is needed to encrypt and decipher codes and is needed by both the user and sender. A solution to this problem is the generation of quantum key distributions. In our experiment, we are now ...


On The Reality Of Mathematics, Brendan Ortmann 2017 Southeastern University - Lakeland

On The Reality Of Mathematics, Brendan Ortmann

Selected Student Publications

Mathematics is an integral cornerstone of science and society at large, and its implications and derivations should be considered. That mathematics is frequently abstracted from reality is a notion not countered, but one must also think upon its physical basis as well. By segmenting mathematics into its different, abstract philosophies and real-world applications, this paper seeks to peer into the space that mathematics seems to fill; that is, to understand how and why it works. Under mathematical theory, Platonism, Nominalism, and Fictionalism are analyzed for their validity and their shortcomings, in addition to the evaluation of infinities and infinitesimals, to ...


The Case Of The Disappearing (And Re-Appearing) Particle, Yakir Aharonov, Eliahu Cohen, Ariel Landau, Avshalom C. Elitzur 2017 Chapman University

The Case Of The Disappearing (And Re-Appearing) Particle, Yakir Aharonov, Eliahu Cohen, Ariel Landau, Avshalom C. Elitzur

Mathematics, Physics, and Computer Science Faculty Articles and Research

A novel prediction is derived by the Two-State-Vector-Formalism (TSVF) for a particle superposed over three boxes. Under appropriate pre- and post-selections, and with tunneling enabled between two of the boxes, it is possible to derive not only one, but three predictions for three different times within the intermediate interval. These predictions are moreover contradictory. The particle (when looked for using a projective measurement) seems to disappear from the first box where it would have been previously found with certainty, appearing instead within the third box, to which no tunneling is possible, and later re-appearing within the second. It turns out ...


Explorations Of Quantum Entanglement, John Stanton 2017 DePauw University

Explorations Of Quantum Entanglement, John Stanton

Student research

This thesis develops an undergraduate level understanding of quantum entanglement by expressing its properties in three unique mediums: mathematical formalism, application in technology and experiment. The mathematical formalism of entanglement is developed by working through theoretical experiments that utilize the entangled polarization states of photons. Notation used to describe entangled photon states is then used to illustrate how other types of entangled quantum states can be used in real technology, such as is the case with quantum computing. Finally, the theoretical predictions associated with entanglement are discussed in reference to two quantum optics experiments.


Exploring The Multi-Mode Structure Of Atom-Generated Squeezed Light, Melissa A. Guidry 2017 College of William and Mary

Exploring The Multi-Mode Structure Of Atom-Generated Squeezed Light, Melissa A. Guidry

Undergraduate Honors Theses

Squeezed states of light, i.e., quantum states exhibiting reduced noise statistics, may be used to greatly enhance the sensitivity of light-based measurements. We study a squeezed vacuum field generated in hot Rb vapor via the polarization self-rotation effect. By propagating a strong pump beam through an atomic vapor cell, we were able to achieve a noise suppression of 2.7 dB below shot noise. Our previous work revealed that this amount of noise suppression may be limited by the excitement of higher order modes in the squeezed field during the atom-light interaction. Once incident on the homodyne detection scheme ...


Neutron-Unbound Excited States Of 23n, M. Jones, T. Baumann, J. Brett, J. Bullaro, P. A. DeYoung, J.E. Finck, N. Frank, K. Hammerton, J. Hinnefeld, Z. Kohley, A. N. Kuchera, J. Pereira, A. Rabeh, J. K. Smith, A. Spyrou, Sharon L. Stephenson, K. Stiefel, M. Tuttle-Timm, R. G.T. Zegers, M. Thoennessen 2017 Michigan State University

Neutron-Unbound Excited States Of 23n, M. Jones, T. Baumann, J. Brett, J. Bullaro, P. A. Deyoung, J.E. Finck, N. Frank, K. Hammerton, J. Hinnefeld, Z. Kohley, A. N. Kuchera, J. Pereira, A. Rabeh, J. K. Smith, A. Spyrou, Sharon L. Stephenson, K. Stiefel, M. Tuttle-Timm, R. G.T. Zegers, M. Thoennessen

Physics and Astronomy Faculty Publications

Neutron unbound states in 23N were populated via proton knockout from an 83.4 MeV/nucleon 24O beam on a liquid deuterium target. The two-body decay energy displays two peaks at E1∼100keV and E2∼1MeV with respect to the neutron separation energy. The data are consistent with shell model calculations predicting resonances at excitation energies of ∼3.6MeV and ∼4.5MeV. The selectivity of the reaction implies that these states correspond to the first and second 3/2− states. The energy of the first state is about 1.3 MeV lower than the first excited 2+ in 24O. This ...


The Two-Time Interpretation And Macroscopic Time-Reversibility, Yakir Aharonov, Eliahu Cohen, Tomer Landsberger 2017 Chapman University

The Two-Time Interpretation And Macroscopic Time-Reversibility, Yakir Aharonov, Eliahu Cohen, Tomer Landsberger

Mathematics, Physics, and Computer Science Faculty Articles and Research

The two-state vector formalism motivates a time-symmetric interpretation of quantum mechanics that entails a resolution of the measurement problem. We revisit a post-selection-assisted collapse model previously suggested by us, claiming that unlike the thermodynamic arrow of time, it can lead to reversible dynamics at the macroscopic level. In addition, the proposed scheme enables us to characterize the classical-quantum boundary. We discuss the limitations of this approach and its broad implications for other areas of physics.


Pion Distribution Amplitude And Quasidistributions, A. V. Radyushkin 2017 Old Dominion University

Pion Distribution Amplitude And Quasidistributions, A. V. Radyushkin

Physics Faculty Publications

We extend our analysis of quasidistributions onto the pion distribution amplitude. Using the formalism of parton virtuality distribution amplitudes, we establish a connection between the pion transverse momentum dependent distribution amplitude Ψ(x, k2⊥) and the pion quasidistribution amplitude (QDA) Qπ(y, p3). We build models for the QDAs from the virtuality-distribution-amplitude-based models for soft transverse momentum dependent distribution amplitudes, and analyze the p3 dependence of the resulting QDAs. As there are many models claimed to describe the primordial shape of the pion distribution amplitude, we present the p3-evolution patterns for models producing some ...


Squeezing Light With Atoms: Generation Of Non-Classical Light Via Four-Wave Mixing, Nathan Super 2017 College of William and Mary

Squeezing Light With Atoms: Generation Of Non-Classical Light Via Four-Wave Mixing, Nathan Super

Science Research Symposium

The goal of the project is to produce a pair of polarization-entangled light fields using four-wave mixing in hot Rb vapor. In this process, interaction of atoms with near-resonant strong control optical field results in strong amplification of a nearly-collinear probe optical field and in generation of a quantum correlated conjugate Stokes optical field. In order to establish the quantum correlation between the Stokes and probe fields, we have adopted a homodyne detection scheme. If the differential noise between the Stokes and probe fields is below the quantum noise limit, then intensity fluctuation entanglement has been achieved, and it is ...


Higher-Harmonic Collective Modes In A Trapped Gas From Second-Order Hydrodynamics, William E. Lewis, Paul Romatschke 2017 University of Colorado Boulder

Higher-Harmonic Collective Modes In A Trapped Gas From Second-Order Hydrodynamics, William E. Lewis, Paul Romatschke

University Libraries Open Access Fund Supported Publications

Utilizing a second-order hydrodynamics formalism, the dispersion relations for the frequencies and damping rates of collective oscillations as well as spatial structure of these modes up to the decapole oscillation in both two- and three- dimensional gas geometries are calculated. In addition to higher-order modes, the formalism also gives rise to purely damped 'non-hydrodynamic' modes. We calculate the amplitude of the various modes for both symmetric and asymmetric trap quenches, finding excellent agreement with an exact quantum mechanical calculation. We find that higher-order hydrodynamic modes are more sensitive to the value of shear viscosity, which may be of interest for ...


Data Collection And Analysis At The Atlas Detector, Savannah Thais 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, Luis Cortez, Areeya Chantasri, Luis Pedro García-Pintos, Justin Dressel, Andrew N. Jordan 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 ...


Digital Commons powered by bepress