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2016

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Full-Text Articles in Physics

Computational Fluid Dynamics Is Key To Better Flying Aircraft, Nihad E. Daidzic Dec 2016

Computational Fluid Dynamics Is Key To Better Flying Aircraft, Nihad E. Daidzic

Aviation Department Publications

No abstract provided.


Analysis Of Drift Effects On The Tokamak Power Scrape-Off Width Using Solps-Iter, E. T. Meier, R. J. Goldston, E. G. Kaveeva, M. A. Makowski, Saskia Mordijck, V. A. Rozhansky, I. Yu Senichenkov, S. P. Voskoboynikov Dec 2016

Analysis Of Drift Effects On The Tokamak Power Scrape-Off Width Using Solps-Iter, E. T. Meier, R. J. Goldston, E. G. Kaveeva, M. A. Makowski, Saskia Mordijck, V. A. Rozhansky, I. Yu Senichenkov, S. P. Voskoboynikov

Arts & Sciences Articles

SOLPS-ITER, a comprehensive 2D scrape-off layer modeling package, is used to examine the physical mechanisms that set the scrape-off width (lambda(q)) for inter-ELM power exhaust. Guided by Goldston's heuristic drift (HD) model, which shows remarkable quantitative agreement with experimental data, this research examines drift effects on lambda(q) in a DIII-D H-mode magnetic equilibrium. As a numerical expedient, a low target recycling coefficient of 0.9 is used in the simulations, resulting in outer target plasma that is sheath limited instead of conduction limited as in the experiment. Scrape-off layer (SOL) particle diffusivity (D-SOL) is scanned from 1 to 0.1 m(2) s(-1). …


Prospects For Observing And Localizing Gravitational-Wave Transients With Advanced Ligo And Advanced Virgo, Benjamin P. Abbott, Marco Cavaglia, For Full List Of Authors, See Publisher's Website. Dec 2016

Prospects For Observing And Localizing Gravitational-Wave Transients With Advanced Ligo And Advanced Virgo, Benjamin P. Abbott, Marco Cavaglia, For Full List Of Authors, See Publisher's Website.

Physics Faculty Research & Creative Works

We present a possible observing scenario for the Advanced LIGO and Advanced Virgo gravitational-wave detectors over the next decade, with the intention of providing information to the astronomy community to facilitate planning for multi-messenger astronomy with gravitational waves. We determine the expected sensitivity of the network to transient gravitational-wave signals, and study the capability of the network to determine the sky location of the source. We report our findings for gravitational-wave transients, with particular focus on gravitational-wave signals from the inspiral of binary neutron-star systems, which are considered the most promising for multi-messenger astronomy. The ability to localize the sources …


Identity‐Based Schemes For A Secured Big Data And Cloud Ict Framework In Smart Grid System, Feng Ye, Yi Qian, Rose Qingyang Hu Dec 2016

Identity‐Based Schemes For A Secured Big Data And Cloud Ict Framework In Smart Grid System, Feng Ye, Yi Qian, Rose Qingyang Hu

Electrical and Computer Engineering Faculty Publications

Smart grid is an intelligent cyber physical system (CPS). The CPS generates a massive amount of data for efficient grid operation. In this paper, a big data‐driven, cloud‐based information and communication technology (ICT) framework for smart grid CPS is proposed. The proposed ICT framework deploys hybrid cloud servers to enhance scalability and reliability of smart grid communication infrastructure. Because the data in the ICT framework contains much privacy of customers and important data for automated controlling, the security of data transmission must be ensured. In order to secure the communications over the Internet in the system, identity‐based schemes are proposed …


Tests Of Lorentz Symmetry In The Gravitational Sector, Aurélien Hees, Quentin G. Bailey, Adrien Bourgoin, Hélène Pihan-Le Bars, Christine Guerlin, Christophe Le Poncin-Lafitte Dec 2016

Tests Of Lorentz Symmetry In The Gravitational Sector, Aurélien Hees, Quentin G. Bailey, Adrien Bourgoin, Hélène Pihan-Le Bars, Christine Guerlin, Christophe Le Poncin-Lafitte

Publications

Lorentz symmetry is one of the pillars of both General Relativity and the Standard Model of particle physics. Motivated by ideas about quantum gravity, unification theories and violations of CPT symmetry, a significant effort has been put the last decades into testing Lorentz symmetry. This review focuses on Lorentz symmetry tests performed in the gravitational sector. We briefly review the basics of the pure gravitational sector of the Standard-Model Extension (SME) framework, a formalism developed in order to systematically parametrize hypothetical violations of the Lorentz invariance. Furthermore, we discuss the latest constraints obtained within this formalism including analyses of the …


Dual Role Of Sb Ions As Electron Traps And Hole Traps In Photorefractive Sn2P2S6 Crystals, Brant E. Kananen, Eric M. Golden, Sergey A. Basun, D. R. Evans, A. A. Grabar, I. M. Stoika, John W. Mcclory, Nancy C. Giles, Larry E. Halliburton Dec 2016

Dual Role Of Sb Ions As Electron Traps And Hole Traps In Photorefractive Sn2P2S6 Crystals, Brant E. Kananen, Eric M. Golden, Sergey A. Basun, D. R. Evans, A. A. Grabar, I. M. Stoika, John W. Mcclory, Nancy C. Giles, Larry E. Halliburton

Faculty Publications

Doping photorefractive single crystals of Sn2P2S6 with antimony introduces both electron and hole traps. In as-grown crystals, Sb3+ (5s2) ions replace Sn2+ ions. These Sb3+ ions are either isolated (with no nearby perturbing defects) or they have a charge-compensating Sn2+ vacancy at a nearest-neighbor Sn site. When illuminated with 633 nm laser light, isolated Sb3+ ions trap electrons and become Sb2+ (5s25p1) ions. In contrast, Sb3+ ions with an adjacent Sn vacancy trap holes during illumination. The hole is primarily …


Plasma Processes And Polymers Third Special Issue On Plasma And Cancer, Mounir Laroussi, Annemie Bogaerts, Nazir Barekzi Dec 2016

Plasma Processes And Polymers Third Special Issue On Plasma And Cancer, Mounir Laroussi, Annemie Bogaerts, Nazir Barekzi

Electrical & Computer Engineering Faculty Publications

(First paragraph) This issue of Plasma Processes and Polymers is the third in a series on the applications of low temperature plasma (LTP) against cancer, or “plasma oncology.” The papers in this issue are inspired from the talks given at the third International Workshop on Plasma for Cancer Treatment (IWPCT) which took place on April 11–12, 2016 in Washington, DC, USA. IWPCT is an international workshop that was created in 2014 as a venue to share cutting edge plasma oncology research. The first IWPCT was held in Washington DC, under the co-chairmanship of Prof. Mounir Laroussi (Old Dominion University) and …


Sdss-Iv Manga: A Serendipitous Observation Of A Potential Gas Accretion Event, Edmond Cheung, David V. Stark, Song Huang, Kate H. R. Rubin, Lihwai Lin, Christy Tremonti, Kai Zhang, Renbin Yan, Dmitry Bizyaev, Médéric Boquien Nov 2016

Sdss-Iv Manga: A Serendipitous Observation Of A Potential Gas Accretion Event, Edmond Cheung, David V. Stark, Song Huang, Kate H. R. Rubin, Lihwai Lin, Christy Tremonti, Kai Zhang, Renbin Yan, Dmitry Bizyaev, Médéric Boquien

Physics and Astronomy Faculty Publications

The nature of warm, ionized gas outside of galaxies may illuminate several key galaxy evolutionary processes. A serendipitous observation by the MaNGA survey has revealed a large, asymmetric Hα complex with no optical counterpart that extends ≈8'' (≈6.3 kpc) beyond the effective radius of a dusty, starbursting galaxy. This Hα extension is approximately three times the effective radius of the host galaxy and displays a tail-like morphology. We analyze its gas-phase metallicities, gaseous kinematics, and emission-line ratios and discuss whether this Hα extension could be diffuse ionized gas, a gas accretion event, or something else. We find …


Sdss-Iv Manga Ifs Galaxy Survey—Survey Design, Execution, And Initial Data Quality, Renbin Yan, Kevin Bundy, David R. Law, Matthew A. Bershady, Brett Andrews, Brian Cherinka, Aleksandar M. Diamond-Stanic, Niv Drory, Nicholas Macdonald, José R. Sánchez-Gallego, Daniel Thomas, David A. Wake, Anne-Marie Weijmans, Kyle B. Westfall, Kai Zhang, Alfonso Aragón-Salamanca, Francesco Belfiore, Dmitry Bizyaev, Guillermo A. Blanc, Michael R. Blanton, Joel Brownstein, Michele Cappellari, Richard D'Souza, Eric Emsellem, Hai Fu, Patrick Gaulme, Mark T. Graham, Daniel Goddard, James E. Gunn, Paul Harding Nov 2016

Sdss-Iv Manga Ifs Galaxy Survey—Survey Design, Execution, And Initial Data Quality, Renbin Yan, Kevin Bundy, David R. Law, Matthew A. Bershady, Brett Andrews, Brian Cherinka, Aleksandar M. Diamond-Stanic, Niv Drory, Nicholas Macdonald, José R. Sánchez-Gallego, Daniel Thomas, David A. Wake, Anne-Marie Weijmans, Kyle B. Westfall, Kai Zhang, Alfonso Aragón-Salamanca, Francesco Belfiore, Dmitry Bizyaev, Guillermo A. Blanc, Michael R. Blanton, Joel Brownstein, Michele Cappellari, Richard D'Souza, Eric Emsellem, Hai Fu, Patrick Gaulme, Mark T. Graham, Daniel Goddard, James E. Gunn, Paul Harding

Physics and Astronomy Faculty Publications

The MaNGA Survey (Mapping Nearby Galaxies at Apache Point Observatory) is one of three core programs in the Sloan Digital Sky Survey IV. It is obtaining integral field spectroscopy for 10,000 nearby galaxies at a spectral resolution of R ~ 2000 from 3622 to 10354 Å. The design of the survey is driven by a set of science requirements on the precision of estimates of the following properties: star formation rate surface density, gas metallicity, stellar population age, metallicity, and abundance ratio, and their gradients; stellar and gas kinematics; and enclosed gravitational mass as a function of radius. We describe …


Extracting Vibration Characteristics Of A Guitar Using Finite Element, Modal Analysis, And Digital Image Correlation Techniques, Kiran Patil, Javad Baqersad, Daniel Ludwigsen, Yaomin Dong Nov 2016

Extracting Vibration Characteristics Of A Guitar Using Finite Element, Modal Analysis, And Digital Image Correlation Techniques, Kiran Patil, Javad Baqersad, Daniel Ludwigsen, Yaomin Dong

Physics Publications

The sound quality generated by the guitar depends on the vibration characteristics (i.e. natural frequencies and mode shapes) of this instrument. Thus, it is of particular interest to the guitar manufacturers to be able to obtain global information about the characteristics of the guitar. Traditional sensors can only measure at discrete locations. However, digital image correlation (DIC) can measure full-field data on the surface of the structure. In the current paper, a finite element (FE) model of a guitar with free boundary configurations was developed using quadratic solid elements. An eigensolution was performed on the FE model to determine its …


Reflective Inverse Diffusion, Kenneth W. Burgi, Jessica Ullom, Michael A. Marciniak, Mark E. Oxley Nov 2016

Reflective Inverse Diffusion, Kenneth W. Burgi, Jessica Ullom, Michael A. Marciniak, Mark E. Oxley

Faculty Publications

Phase front modulation was previously used to refocus light after transmission through scattering media. This process has been adapted here to work in reflection. A liquid crystal spatial light modulator is used to conjugate the phase scattering properties of diffuse reflectors to produce a converging phase front just after reflection. The resultant focused spot had intensity enhancement values between 13 and 122 depending on the type of reflector. The intensity enhancement of more specular materials was greater in the specular region, while diffuse reflector materials achieved a greater enhancement in non-specular regions, facilitating non-mechanical steering of the focused spot. Scalar …


Measurement Of Electroweak Production Of A W Boson And Two Forward Jets In Proton-Proton Collisions At √S = 8 Tev, M M. Baarmand, Vallary Bhopatkar, Stefano Colafranceschi, Marcus Hohlmann, H Kalakhety, D Noonan, Tuhin S. Roy, Francisco X. Yumiceva, Cms Collaboration Nov 2016

Measurement Of Electroweak Production Of A W Boson And Two Forward Jets In Proton-Proton Collisions At √S = 8 Tev, M M. Baarmand, Vallary Bhopatkar, Stefano Colafranceschi, Marcus Hohlmann, H Kalakhety, D Noonan, Tuhin S. Roy, Francisco X. Yumiceva, Cms Collaboration

Aerospace, Physics, and Space Science Faculty Publications

A measurement is presented of the cross section for the electroweak production of a W boson in association with two jets in proton-proton collisions at a center-of-mass energy of 8 TeV. The data set was collected with the CMS detector and corresponds to an integrated luminosity of 19.3 fb−1. The measured fiducial cross section for W bosons decaying to electrons or muons and for pTj1> 60 GeV, pTj2> 50 GeV, |ηj| < 4.7, and mjj> 1000 GeV is 0.42 ± 0.04 (stat) ± 0.09 (syst) ± 0.01 (lumi) pb. This result is consistent with the standard model leading-order prediction of 0.50 ± 0.02 (scale) …


Exchange Bias Effects In Iron Oxide-Based Nanoparticle Systems, Manh-Huong Phan, Javier Alsonso, Hafsa Khurshid, Paula Lampen-Kelley, Sayan Chandra, Kristen Stojak Repa, Zohreh Nemati, Raja Das, Óscar Iglesias, Hariharan Srikanth Nov 2016

Exchange Bias Effects In Iron Oxide-Based Nanoparticle Systems, Manh-Huong Phan, Javier Alsonso, Hafsa Khurshid, Paula Lampen-Kelley, Sayan Chandra, Kristen Stojak Repa, Zohreh Nemati, Raja Das, Óscar Iglesias, Hariharan Srikanth

Physics Faculty Publications

The exploration of exchange bias (EB) on the nanoscale provides a novel approach to improving the anisotropic properties of magnetic nanoparticles for prospective applications in nanospintronics and nanomedicine. However, the physical origin of EB is not fully understood. Recent advances in chemical synthesis provide a unique opportunity to explore EB in a variety of iron oxide-based nanostructures ranging from core/shell to hollow and hybrid composite nanoparticles. Experimental and atomistic Monte Carlo studies have shed light on the roles of interface and surface spins in these nanosystems. This review paper aims to provide a thorough understanding of the EB and related …


Avalanche Statistics From Data With Low Time Resolution, Michael Leblanc, Aya Nawano, Wendelin J. Wright, Xiaojun Gu, Jonathan T. Uhl, Karin A. Dahmen Nov 2016

Avalanche Statistics From Data With Low Time Resolution, Michael Leblanc, Aya Nawano, Wendelin J. Wright, Xiaojun Gu, Jonathan T. Uhl, Karin A. Dahmen

Faculty Journal Articles

Extracting avalanche distributions from experimental microplasticity data can be hampered by limited time resolution. We compute the effects of low time resolution on avalanche size distributions and give quantitative criteria for diagnosing and circumventing problems associated with low time resolution. We show that traditional analysis of data obtained at low acquisition rates can lead to avalanche size distributions with incorrect power-law exponents or no power-law scaling at all. Furthermore, we demonstrate that it can lead to apparent data collapses with incorrect power-law and cutoff exponents. We propose new methods to analyze low-resolution stress-time series that can recover the size distribution …


Connecting Self-Efficacy And Views About Nature Of Science In Undergraduate Research Experiences, Gina Quan, Andrew Elby Nov 2016

Connecting Self-Efficacy And Views About Nature Of Science In Undergraduate Research Experiences, Gina Quan, Andrew Elby

Faculty Publications

Undergraduate research can support students’ more central participation in physics. We analyze markers of two coupled shifts in participation: changes in students’ views about the nature of science coupled to shifts in self-efficacy toward physics research. Students in the study worked with faculty and graduate student mentors on research projects while also participating in a seminar where they learned about research and reflected on their experiences. In classroom discussions and in clinical interviews, students described gaining more nuanced views about the nature of science, specifically related to who can participate in research and what participation in research looks like. This …


All-Optical Cooling Of Fermi Gases Via Pauli Inhibition Of Spontaneous Emission, Roberto Onofrio Nov 2016

All-Optical Cooling Of Fermi Gases Via Pauli Inhibition Of Spontaneous Emission, Roberto Onofrio

Dartmouth Scholarship

A technique is proposed to cool Fermi gases to the regime of quantum degeneracy based on the expected inhibition of spontaneous emission due to the Pauli principle. The reduction of the linewidth for spontaneous emission originates a corresponding reduction of the Doppler temperature, which under specific conditions may give rise to a runaway process through which fermions are progressively cooled. The approach requires a combination of a magneto-optical trap as a cooling system and an optical dipole trap to enhance quantum degeneracy. This results in expected Fermi degeneracy factors T/TF comparable to the lowest values recently achieved, with potential for …


Properties Of The Schrödinger Theory Of Electrons In Electromagnetic Fields, Viraht Sahni, Xiao-Yin Pan Nov 2016

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, …


Results Of The Deepest All-Sky Survey For Continuous Gravitational Waves On Ligo S6 Data Running On The Einstein@Home Volunteer Distributed Computing Project, B. P. Abbott, R. Abbott, T. D. Abbott, M. R. Abernathy, F. Acernese, K. Ackley, C. Adams, T. Adams, Marc Favata, Shaon Ghosh Nov 2016

Results Of The Deepest All-Sky Survey For Continuous Gravitational Waves On Ligo S6 Data Running On The Einstein@Home Volunteer Distributed Computing Project, B. P. Abbott, R. Abbott, T. D. Abbott, M. R. Abernathy, F. Acernese, K. Ackley, C. Adams, T. Adams, Marc Favata, Shaon Ghosh

Department of Physics and Astronomy Faculty Scholarship and Creative Works

We report results of a deep all-sky search for periodic gravitational waves from isolated neutron stars in data from the S6 LIGO science run. The search was possible thanks to the computing power provided by the volunteers of the Einstein@Home distributed computing project. We find no significant signal candidate and set the most stringent upper limits to date on the amplitude of gravitational wave signals from the target population. At the frequency of best strain sensitivity, between 170.5 and 171 Hz we set a 90% confidence upper limit of 5.5×10-25, while at the high end of our frequency range, around …


Magnon Spin Nernst Effect In Antiferromagnets, Vladimir Zyuzin, Alexey Kovalev Nov 2016

Magnon Spin Nernst Effect In Antiferromagnets, Vladimir Zyuzin, Alexey Kovalev

Department of Physics and Astronomy: Faculty Publications

We predict that a temperature gradient can induce a magnon-mediated spin Hall response in an antiferromagnet with nontrivial magnon Berry curvature. We develop a linear response theory which gives a general condition for a Hall current to be well defined, even when the thermal Hall response is forbidden by symmetry. We apply our theory to a honeycomb lattice antiferromagnet and discuss a role of magnon edge states in a finite geometry.


A First Targeted Search For Gravitational-Wave Bursts From Core-Collapse Supernovae In Data Of First-Generation Laser Interferometer Detectors, B. P. Abbott, R. Abbott, T. D. Abbott, M. R. Abernathy, F. Acernese, K. Ackley, C. Adams, Marc Favata, Shaon Ghosh, Rodica Martin Nov 2016

A First Targeted Search For Gravitational-Wave Bursts From Core-Collapse Supernovae In Data Of First-Generation Laser Interferometer Detectors, B. P. Abbott, R. Abbott, T. D. Abbott, M. R. Abernathy, F. Acernese, K. Ackley, C. Adams, Marc Favata, Shaon Ghosh, Rodica Martin

Department of Physics and Astronomy Faculty Scholarship and Creative Works

We present results from a search for gravitational-wave bursts coincident with two core-collapse supernovae observed optically in 2007 and 2011. We employ data from the Laser Interferometer Gravitational-wave Observatory (LIGO), the Virgo gravitational-wave observatory, and the GEO 600 gravitational-wave observatory. The targeted core-collapse supernovae were selected on the basis of (1) proximity (within approximately 15 Mpc), (2) tightness of observational constraints on the time of core collapse that defines the gravitational-wave search window, and (3) coincident operation of at least two interferometers at the time of core collapse. We find no plausible gravitational-wave candidates. We present the probability of detecting …


Quantum Dot Band Gap Investigations, John Ryan Peterson Nov 2016

Quantum Dot Band Gap Investigations, John Ryan Peterson

Student Works

Improving solar panel efficiency has become increasingly important as the world searches for cheap renewable energy. Recent developments in the industry have focused on multi-layer cells, some of which use semiconducting dyes to absorb light in place of crystalline solids. In this paper, I characterize various dyes recently synthesized for use in solar panels. These dyes contain semiconducting nanoparticles enclosed primarily by the protein ferritin to limit particle size. The band gaps were measured using either optical absorption spectroscopy or measuring the photoluminescence spectrum, depending on the type of semiconductor. The results indicate that both manganese oxide and lead sulfide …


Probing A Panoply Of Curvaton-Decay Scenarios Using Cmb Data, Tristan L. Smith, D. Grin Nov 2016

Probing A Panoply Of Curvaton-Decay Scenarios Using Cmb Data, Tristan L. Smith, D. Grin

Physics & Astronomy Faculty Works

In the curvaton scenario, primordial curvature perturbations are produced by a second field that is subdominant during inflation. Depending on how the curvaton decays [possibly producing baryon number, lepton number, or cold dark matter (CDM)], mixtures of correlated isocurvature perturbations are produced, allowing the curvaton scenario to be tested using cosmic microwave background (CMB) data. Here, a full range of 27 curvaton-decay scenarios is compared with CMB data, placing limits on the curvaton fraction at decay, rD, and the lepton asymmetry, ξlep. If baryon number is generated by curvaton decay and CDM before (or vice versa), these limits imply specific …


Triode For Magnetic Flux Quanta, V.K. Vlasko-Vlasov, F. Caluto, Timothy Benseman, D. Rosenmann, W.K. Kwok Nov 2016

Triode For Magnetic Flux Quanta, V.K. Vlasko-Vlasov, F. Caluto, Timothy Benseman, D. Rosenmann, W.K. Kwok

Publications and Research

In an electronic triode, the electron current emanating from the cathode is regulated by the electric potential on a grid between the cathode and the anode. Here we demonstrate a triode for single quantum magnetic field carriers, where the flow of individual magnetic vortices in a superconducting film is regulated by the magnetic potential of striae of soft magnetic strips deposited on the film surface. By rotating an applied in-plane field, the magnetic strip potential can be varied due to changes in the magnetic charges at the strip edges, allowing accelerated or retarded motion of magnetic vortices inside the superconductor. …


The Quenching Timescale And Quenching Rate Of Galaxies, Jianhui Lian, Renbin Yan, Kai Zhang, Xu Kong Nov 2016

The Quenching Timescale And Quenching Rate Of Galaxies, Jianhui Lian, Renbin Yan, Kai Zhang, Xu Kong

Physics and Astronomy Faculty Publications

The average star formation rate (SFR) in galaxies has been declining since the redshift of 2. A fraction of galaxies quench and become quiescent. We constrain two key properties of the quenching process: the quenching timescale and the quenching rate among galaxies. We achieve this by analyzing the galaxy number density profile in NUV−u color space and the distribution in NUV−u versus ui color–color diagram with a simple toy-model framework. We focus on galaxies in three mass bins between 1010 and 1010.6 M . In the NUV−u versus ui color–color …


Selective Growth Of Epitaxial Sr2Iro4 By Controlling Plume Dimensions In Pulsed Laser Deposition, Sung S. Ambrose Seo, J. Nichols, J. Hwang, Jsaminka Terzic, John H. Gruenewald, Maryam Souri, Justin K. Thompson, John G. Connell, Gang Cao Nov 2016

Selective Growth Of Epitaxial Sr2Iro4 By Controlling Plume Dimensions In Pulsed Laser Deposition, Sung S. Ambrose Seo, J. Nichols, J. Hwang, Jsaminka Terzic, John H. Gruenewald, Maryam Souri, Justin K. Thompson, John G. Connell, Gang Cao

Physics and Astronomy Faculty Publications

We report that epitaxial Sr2IrO4 thin-films can be selectively grown using pulsed laser deposition (PLD). Due to the competition between the Ruddlesden-Popper phases of strontium iridates (Srn+1IrnO3n+1), conventional PLD methods often result in mixed phases of Sr2IrO4 (n = 1), Sr3Ir2O7 (n = 2), and SrIrO3 (n = ∞). We have discovered that reduced PLD plume dimensions and slow deposition rates are the key for stabilizing pure Sr2IrO4 phase thin-films, identified by real-time in-situ monitoring of their optical spectra. …


Theory Of Spin Loss At Metallic Interfaces, Kirill D. Belashchenko, Alexey Kovalev, Mark Van Schilfgaarde Nov 2016

Theory Of Spin Loss At Metallic Interfaces, Kirill D. Belashchenko, Alexey Kovalev, Mark Van Schilfgaarde

Department of Physics and Astronomy: Faculty Publications

Interfacial spin-flip scattering plays an important role in magnetoelectronic devices. Spin loss at metallic interfaces is usually quantified by matching the magnetoresistance data for multilayers to the Valet-Fert model, while treating each interface as a fictitious bulk layer whose thickness is δ times the spin-diffusion length. By employing the properly generalized circuit theory and the scattering matrix approaches, we derive the relation of the parameter δ to the spin-flip transmission and reflection probabilities at an individual interface. It is found that δ is proportional to the square root of the probability of spin-flip scattering. We calculate the spin-flip scattering probabilities …


Theory Of Spin Loss At Metallic Interfaces, Kirill Belashchenko, Alexey Kovalev, Mark Van Schilfgaarde Nov 2016

Theory Of Spin Loss At Metallic Interfaces, Kirill Belashchenko, Alexey Kovalev, Mark Van Schilfgaarde

Materials Research Science and Engineering Center: Faculty Publications

Interfacial spin-flip scattering plays an important role in magnetoelectronic devices. Spin loss at metallic interfaces is usually quantified by matching the magnetoresistance data for multilayers to the Valet-Fert model, while treating each interface as a fictitious bulk layer whose thickness is δ times the spin-diffusion length. By employing the properly generalized circuit theory and the scattering matrix approaches, we derive the relation of the parameter δ to the spin-flip transmission and reflection probabilities at an individual interface. It is found that δ is proportional to the square root of the probability of spin-flip scattering. We calculate the spin-flip scattering probabilities …


Splitting Nodes And Linking Channels: A Method For Assembling Biocircuits From Stochastic Elementary Units, Cameron Ferwerda, Ovidiu Lipan Nov 2016

Splitting Nodes And Linking Channels: A Method For Assembling Biocircuits From Stochastic Elementary Units, Cameron Ferwerda, Ovidiu Lipan

Physics Faculty Publications

Akin to electric circuits, we construct biocircuits that are manipulated by cutting and assembling channels through which stochastic information flows. This diagrammatic manipulation allows us to create a method which constructs networks by joining building blocks selected so that (a) they cover only basic processes; (b) it is scalable to large networks; (c) the mean and variance-covariance from the Pauli master equation form a closed system; and (d) given the initial probability distribution, no special boundary conditions are necessary to solve the master equation. The method aims to help with both designing new synthetic signaling pathways and quantifying naturally existing …


Decomposing Transverse Momentum Balance Contributions For Quenched Jets In Pbpb Collisions At √Snn=2.76 Tev, M M. Baarmand, Vallary Bhopatkar, Stefano Colafranceschi, Marcus Hohlmann, D Noonan, Tuhin S. Roy, Francisco X. Yumiceva, Cms Collaboration Nov 2016

Decomposing Transverse Momentum Balance Contributions For Quenched Jets In Pbpb Collisions At √Snn=2.76 Tev, M M. Baarmand, Vallary Bhopatkar, Stefano Colafranceschi, Marcus Hohlmann, D Noonan, Tuhin S. Roy, Francisco X. Yumiceva, Cms Collaboration

Aerospace, Physics, and Space Science Faculty Publications

Interactions between jets and the quark-gluon plasma produced in heavy ion collisions are studied via the angular distributions of summed charged-particle transverse momenta (pT) with respect to both the leading and subleading jet axes in high-pT dijet events. The contributions of charged particles in different momentum ranges to the overall event pT balance are decomposed into short-range jet peaks and a long-range azimuthal asymmetry in charged-particle pT. The results for PbPb collisions are compared to those in pp collisions using data collected in 2011 and 2013, at collision energy sNN=2.76 TeV with integrated luminosities of 166 μb−1 and 5.3 pb−1, …


Research Update: The Mechanocaloric Potential Of Spin Crossover Compounds, Karl G. Sandeman Nov 2016

Research Update: The Mechanocaloric Potential Of Spin Crossover Compounds, Karl G. Sandeman

Publications and Research

We present a first evaluation of the potential for spin crossover (SCO) compounds to be considered as a new class of giant mechanocaloric effect materials. From literature data on the variation of the spin crossover temperature with pressure, we estimate the maximum available adiabatic temperature change for several compounds and the relatively low pressures that may be required to observe these effects.