Physics Commons^™

Action Principle For Continuous Quantum Measurement, A. Chantasri, Justin Dressel, Andrew N. Jordan

Mathematics, Physics, and Computer Science Faculty Articles and Research

We present a stochastic path integral formalism for continuous quantum measurement that enables the analysis of rare events using action methods. By doubling the quantum state space to a canonical phase space, we can write the joint probability density function of measurement outcomes and quantum state trajectories as a phase space path integral. Extremizing this action produces the most likely paths with boundary conditions defined by preselected and postselected states as solutions to a set of ordinary differential equations. As an application, we analyze continuous qubit measurement in detail and examine the structure of a quantum jump in the Zeno …

The Fine-Scale Structure Of The Trade Wind Cumuli Over Barbados – An Introduction To The Carriba Project, H. Siebert, M. Beals, J. Bethke, E. Bierwirth, T. Conrath, K. Dieckmann, F. Ditas, A. Ehrlich, D. Farrell, S. Hartmann, M. A. Izaguirre, J. Katzwinkel, L. Nuijens, G. Roberts, M. Schäfer, R. A. Shaw, T. Schmeissner, I. Serikov, B. Stevens, F. Stratmann, B. Wehner, M. Wendisch, F. Werner, H. Wex

Michigan Tech Publications, Part 1

The CARRIBA (Cloud, Aerosol, Radiation and tuRbulence in the trade wInd regime over BArbados) project, focused on high resolution and collocated measurements of thermodynamic, turbulent, microphysical, and radiative properties of trade wind cumuli over Barbados, is introduced. The project is based on two one-month field campaigns in November 2010 (climatic wet season) and April 2011 (climatic dry season). Observations are based on helicopter-borne and ground-based measurements in an area of 100 km2 off the coast of Barbados. CARRIBA is accompanied by long-term observations at the Barbados Cloud Observatory located at the East coast of Barbados since early in 2010 and …

Selectivity Of Silicon Dioxide On Planner Graphite, John Wilcox, Dr. Robert Davis

Journal of Undergraduate Research

BYU’s Nanotube Research Group is currently searching for a method to attach and shorten carbon nanotubes (CNTs) on the tips of Atomic Force Microscope (AFM) probes (image 1). Many have shown that short CNTs grown on the end of AFM probes greatly enhance the resolution and utility of the AFM. With shortened CNTs securely attached to the tip of an AFM probe, the microscope resolution could be improved as much as 5 times. It has been shown that features as small as 1.5nm can be measured . CNTs are strong and have small diameters which make them ideal for scanning …

Characteristic Acoustical Properties Of A Theater In The Round, David Nutter, Dr. Timothy Leishman

Journal of Undergraduate Research

Architectural Acoustics is a field of study with many applications in building design, including office spaces, concert halls, and recording studios. Theaters must be carefully designed so that the speech intelligibility of actors is adequate for the audience. Since theater design is varied and unique to each venue, careful planning in theater design is necessary to achieve a listening environment acceptable to proscribed standards. Although tools exist to simulate a room and predict its acoustical properties, testing must be performed in a completed structure to determine if any changes need to be made.

Micro-Furnace Development For Single-Crystal X-Ray Diffraction Experiments, Brett Guisti

Journal of Undergraduate Research

High-temperature x-ray diffraction experiments have long been of interest for the characterization of materials with phase transitions and other structural variations above room temperature. Examples include cubic zirconia transitioning from cubic to tetragonal below 500°C, β-Alumina gradually moving from an ordered to a disordered state as temperature increases, and superionic conductors like Bi4V2O11. With a more complete understanding of the microscopic structural transitions, the origins of macroscopic properties can be identified.

The Growth Of Single-Walled Carbon Nanotubes On Atomic Force Microscope Tips, Michael Clemens, Dr. Robert Davis

Journal of Undergraduate Research

The Atomic Force Microscope (AFM) is a powerful instrument that has many applications in various fields of scientific research. It has the ability to image surfaces without requiring a high vacuum and has the ability to image samples that are in a fluid. It also is able to image surfaces without damaging them, and doesn’t require as much time in sample preparation. It has the resolution capability on the order of tens of nanometers (nm), which is one millionth of a meter. These qualities make the AFM very useful in doing scientific research.

Direct Measurement Of Absorption Rates For Laser High-Order Harmonics Generated In Helium And Neon, Eric Christensen, Dr. Justin Peatross

Journal of Undergraduate Research

Extreme ultraviolet (EUV) light can be generated through the interaction of a high-intensity laser beam with atoms. When an intense laser pulse hits an atom, its outer electron is pulled away from the atom. The electric field of the laser may then pull the electron back to the atom. When the electron and atom collide, a photon can be emitted.1 As the laser interacts with many atoms near the focus of the beam, the emitted photons build up coherently in the forward direction, creating a highly-directional beam of light. In Dr. Justin Peatross’s lab we work on ways to optimize …

Data Reduction And Publication Of Byu’S Ccd Images Of Comet Hyakutake, Kimball Staples, Nephi Thompson, Dr. J. Ward Moody

Journal of Undergraduate Research

In March 1996, Dr. J. Ward Moody and Dr. Clark Christiansen obtained a series of approximately 120 CCD (solid state electronic) images of Comet Hyakutake. The images were taken at the National Optical Astronomy Observatory on Kitt Peak, near Tucson, Arizona. The large angle Buffell- Schmidt Telescope that was used is one of the best comet-viewing telescopes in the world because of its expanded field of view. The data obtained is the most extensive coverage of a comet tail to date with a modern solid-state detector.

A Ccd Photometric Search For Variable Stars In The Open Cluster Ngc 188, Andrew Davis, Dr. Eric Hintz

Journal of Undergraduate Research

The old open cluster NGC 188 is unique because of its large number of W UMa type contact binaries. This allows astronomers to use these stars to refine models of the origin and evolution of these systems. Also because of its age, NGC 188 may display a wide range of contact binary systems, from the W UMa binaries to the highly evolved FK Comae type star in which the two stellar cores have coalesced. It was our goal to find and classify new variable stars in this cluster.

Understanding The Absorption Edge Energy Shift Of Thorium Dioxide, Uranium Oxide, And Uranium Nitride In The Euv *Or* Optical Applications Of Uranium Thin-Film Compounds For The Extreme Ultraviolet And Soft X-Ray Region, Richard L. Sandberg, Dr. David D. Allred

Journal of Undergraduate Research

Recently, the extreme ultraviolet (EUV) and soft x-ray region of the electromagnetic spectrum (between about 1 and 100 nm in wavelength or 20 eV to 5 keV photon energy) has become increasingly important in technological applications. The next generation of optical technologies will include EUV astronomy, high resolution soft x-ray microscopy for medical/materials science imaging, and EUV computer lithography. These technologies all require optical devices: mirrors, lenses, and other imaging equipment. The Brigham Young University’s EUV Optics research team has been studying the properties of uranium as an EUV optical material for several years. Here I review the research I …

Charactering Titanium Dioxide By Use Of Transmission Electron Microscope, Jason Neff, Dr. Richard Vanfleet

Journal of Undergraduate Research

The original title submitted for my research was “Stacking Faults in GaN”. This study was aimed at employing the use of the Transmission Electron Microscope (TEM) to understand and image defects in the crystal lattice of Gallium Nitride (GaN) that lead to stacking faults. Because of difficulties in the preparation of the material we decided to use the resources and time granted us to work on a project in conjunction with some individuals in the chemistry department. This new project is consistent with the prior investigation, in that the same procedures would be followed, with the same equipment, but with …

Variable Star Research From The Musk Observatory, Miriam Stevens, Dr. Clark Christensen

Journal of Undergraduate Research

For my project, I planned on using the telescope at the Musk Observatory to study the variable star IP Uma. The MUSK Observatory is located about five miles away from the small town Hanksville, UT at the Mars Desert Research Station(MDRS). I have had several opportunities to go to the MDRS with the BYU chapter Mars Society. The Mars Society is a worldwide organization that tries to further the exploration of Mars. The Mars Society owns the MDRS and sends groups of scientists there from all over the world to simulate living on Mars and to conduct Mars related research. …

Diode Laser Stabilization, Brian Neyenhuis

Journal of Undergraduate Research

Over the course of this grant, we have made considerable progress on our laser. We tested an anti-reflection coated diode in our setup, and although the anti-reflective coatings appear to be good, we did not see considerable improvement in scan range. However by experimenting with the geometry of the laser and implementing current feed-forward we were able to improve the scan range from about 9 GHz to greater than 50 GHz, more than sufficient for use in our atomic clock. We found a regular mode hop when attempting to scan over 50 GHz. We considered various etalons inside the cavity …

Energization Of Charged Particles In A Time-Dependent Chaotic Magnetic Field, Xiaocan Li

Von Braun Symposium Student Posters

No abstract provided.

Dynamic Optical Sampling By Cavity Tuning And Its Application In Lidar, Lin Yang, Jinsong Nie, Lingze Duan

Von Braun Symposium Student Posters

No abstract provided.

Method And Implementation Of Absolute Near Cylindrical Wavefront Testing, Ayshah Alatawi

Von Braun Symposium Student Posters

No abstract provided.

Hydromagnetic Waves In A Compressed Dipole Field Via Field-Aligned Klein-Gordon Equations, Jinlei Zheng

Von Braun Symposium Student Posters

No abstract provided.

Sample Preparation For Trace Element Analysis Of Commercial Artists’ Paints Using Pixe, Silas Menlo Scott, Dr. Lawrence Rees

Journal of Undergraduate Research

Particle Induced X-Ray Emission (PIXE) has been used extensively in the study of items of artistic interest. One area of interest has been determining the chemical composition of various artists’ materials.1

Visualization Of Optical Wave Propagation In Femtosecond Photoemission Electron Microscopy, Rolf Kӧnenkamp, Robert Campbell Word, Joseph Fitzgerald

Physics Faculty Publications and Presentations

Photoemission electron microscopy (PEEM) combines in a unique way photon probing and electron imaging. The imaging electrons are generated in a photoelectric process by illuminating the sample with ultra-violet or x-ray light. After generation these electrons are accelerated and introduced into an electron-optical system to produce a microscopic image of the specimen surface. The advantages of PEEM are manifold:

The avoidance of electron beam exposure makes PEEM a much gentler method than standard electron microscopy. This advantage is important when fragile organic or biological structures are studied. PEEM is also highly surface sensitive, since the photoelectrons typically escape the sample …

Electrostatic Discharge In Solids, Allen Andersen, Jr Dennison

Graduate Student Presentations

No abstract provided.

Zno Nanoneedle/H2o Solid-Liquid Heterojunction-Based Self-Powered Ultraviolet Detector, Qinghao Li, Lin Wei, Yanru Xie, Kai Zhang, Lei Liu, Dapeng Zhu, Jun Jiao, Yanxue Chen, Shishen Yan, Guolei Liu, Liangmo Mei

Physics Faculty Publications and Presentations

ZnO nanoneedle arrays were grown vertically on a fluorine-doped tin oxide-coated glass by hydrothermal method at a relatively low temperature. A self-powered photoelectrochemical cell-type UV detector was fabricated using the ZnO nanoneedles as the active photoanode and H2O as the electrolyte. This solid-liquid heterojunction offers an enlarged ZnO/water contact area and a direct pathway for electron transport simultaneously. By connecting this UV photodetector to an ammeter, the intensity of UV light can be quantified using the output short-circuit photocurrent without a power source. High photosensitivity, excellent spectral selectivity, and fast photoresponse at zero bias are observed in this UV detector. …

Dynamics Underlying The Gaussian Distribution Of The Classical Harmonic Oscillator In Zero-Point Radiation, Wayne Cheng-Wei Huang, Herman Batelaan

Department of Physics and Astronomy: Faculty Publications

Stochastic electrodynamics (SED) predicts a Gaussian probability distribution for a classical harmonic oscillator in the vacuum field. This probability distribution is identical to that of the ground state quantum harmonic oscillator. Thus, the Heisenberg minimum uncertainty relation is recovered in SED. To understand the dynamics that give rise to the uncertainty relation and the Gaussian probability distribution, we perform a numerical simulation and follow the motion of the oscillator. The dynamical information obtained through the simulation provides insight to the connection between the classic double-peak probability distribution and the Gaussian probability distribution. A main objective for SED research is to …

Radiation Induced Conductivity And Cathodoluminescence Of Disordered Sio2, Jr Dennison

Presentations

No abstract provided.

Sapling Learning's Online Homework System For Science Courses, Jon Monahan

Physics Seminars

Created and supported by educators, Sapling Learning’s online homework drives student success and saves educators time.

Passionately Crafted Content: Sapling Learning authors are experienced educators. They are passionate about creating problem sets, targeted instructional feedback, and solutions which both challenge and guide students. Student errors are met with more than just hints. Authors write the same quality, detailed feedback that they would deliver to students in person. Multi-step tutorials and engaging, intuitive question types lead students through a dynamic study process with variation that strengthens comprehensive understanding.

Targeted Instructional Feedback: Every question and tutorial from Sapling Learning is embedded with …

Detection Of Ch4 In The Gv Tau N Protoplanetary Disk, David Horne, Erika Gibb

Physics Faculty Works

T Tauri stars are low mass young stars that may serve as analogs to the early solar system. Observations of organic molecules in the protoplanetary disks surrounding T Tauri stars are important for characterizing the chemical and physical processes that lead to planet formation. Searches for undetected molecules, particularly in the inner, planet forming regions of these disks are important for testing protoplanetary disk chemical models and for understanding the evolution of volatiles through the star and planet formation process. We used NIRSPEC on Keck 2 to perform a high resolution (λ/Δλ ~ 25,000) L-band survey of T Tauri star …

Optics And Spectroscopy In Massive Electrodynamic Theory, Adam Caccavano

Dissertations and Theses

The kinematics and dynamics for plane wave optics are derived for a massive electrodynamic field by utilizing Proca's theory. Atomic spectroscopy is also examined, with the focus on the 21 cm radiation due to the hyperfine structure of hydrogen. The modifications to Snell's Law, the Fresnel formulas, and the 21 cm radiation are shown to reduce to the familiar expressions in the limit of zero photon mass.

Rainich-Type Conditions For Null Electrovacuum Spacetimes Ii, Charles G. Torre

Research Vignettes

In this second of two worksheets I continue describing local Rainich-type conditions which are necessary and sufficient for the metric to define a null electrovacuum. In other words, these conditions, which I will call the null electrovacuum conditions, guarantee the existence of a null electromagnetic field such that the metric and electromagnetic field satisfy the Einstein-Maxwell equations. When it exists, the electromagnetic field is easily constructed from the metric. In this worksheet I consider the null electrovacuum conditions which apply when a certain null geodesic congruence determined by the metric is twisting. I shall illustrate the these conditions using a …

Modeling The Atomic And Electronic Structure Of Metal-Metal, Metal-Semiconductor And Semiconductor-Oxide Interfaces, Ganesh Krishna Hegde

Open Access Dissertations

The continuous downward scaling of electronic devices has renewed attention on the importance of the role of material interfaces in the functioning of key components in electronic technology in recent times. It has also brought into focus the utility of

atomistic modeling in providing insights from a materials design perspective. In this thesis, a combination of Semi Empirical Tight-Binding (TB), first-principles Density

Functional Theory and Reactive Molecular Dynamics (MD) modeling is used to study aspects of the electronic and atomic structure of three such 'canonical' material interfaces - Metal-Metal, Metal-Semiconductor and Semiconductor oxide interfaces.

An important contribution of this thesis …

Astr 407

Department of Physics and Astronomy: Syllabi

No abstract provided.

Ground-Based Observations With A Rayleigh-Mie-Raman Lidar From 15-120 Km, Leda Sox, Vincent B. Wickwar, Joshua P. Herron, David L. Barton, Matthew T. Emerick

Graduate Student Posters

Rayleigh lidar systems have historically made ground-based observations of the upper atmosphere (stratosphere and mesosphere) from 35-90 km. This technology has helped fill the data collection gap between the troposphere and space. Recently our Rayleigh lidar group at the Atmospheric Lidar Observatory on the campus of Utah State University (42° N, 112° W) upgraded the original lidar system in order to extend the measurement range for neutral densities and temperatures to higher altitudes and has increased the upper limit, so far, from 90 to 110 km. Next, we will extend the lower altitude limit downward to 15 km. This will …