Review Of Elastic Light Scattering From Single Aerosol Particles And Application In Bioaerosol Detection,
2022
CCDC-US Army Research Laboratory, Adelphi, MD
Review Of Elastic Light Scattering From Single Aerosol Particles And Application In Bioaerosol Detection, Yong-Le Pan, Kevin B. Aptowicz, Jessica Arnold, Samuel Cheng, Aimable Kalume, Patricio Piedra, Chuji Wang, Joshua Santarpia, Gorden Videen
Physics & Engineering Faculty Publications
Elastic light scattering (ELS) from single micron-sized particles has been used as a fast, non-destructive diagnostic tool in life science, physics, chemistry, climatology, and astrophysics. Due to the large scattering cross-section, ELS can be used to find trace amounts of suspect particles such as bioaerosols among complex, diverse atmospheric aerosols, based on single-particle interrogation. In this article, we briefly summarized the main computational models and instrumentation developed for ELS, then reviewed how properties like particle size, refractive index, degree of symmetry, and surface roughness, in addition to packing density, shape of primary particles in an aggregate, and special helix structures …
Charge Transport And Spin Dynamics Of Color Centers In Diamond,
2022
The Graduate Center, City University of New York
Charge Transport And Spin Dynamics Of Color Centers In Diamond, Damon Daw
Dissertations, Theses, and Capstone Projects
Solid state defects in diamond are promising candidates for room temperature quantum information processors (1, 3, 5). Chief among these defects is the nitrogen vacancy center (‘NV center’ or ‘NV’). The NV has long coherence times (at 300K) and its state is easily initialized, manipulated and read out (5). However, the outstanding issue of entangling NV centers in a scalable fashion, at room temperature remains a challenge. This thesis presents experimental and theoretical work aimed at achieving this goal by developing the ‘flying qubit’ framework in (1). This method for remote entanglement utilizes a charge carrier (initialized into a definite …
Modeling Defect Mediated Color-Tunability In Leds With Eu-Doped Gan-Based Active Layers,
2022
Lehigh University
Modeling Defect Mediated Color-Tunability In Leds With Eu-Doped Gan-Based Active Layers, Hayley J. Austin, Brandon Mitchell, Dolf Timmerman, Jun Tatebayashi, Shuhei Ichikawa, Yasufumi Fujiwara, Volkmar Dierolf
Physics & Engineering Faculty Publications
Color tunability from red to orange to yellow has been demonstrated in GaN-based LED devices with Eu-doped GaN layers as the active region. Under current injection, this is achieved by varying the current density and the pulse conditions. The underlying mechanism behind this color tunability is a redistribution of energy among the D-5(J) states of a Eu3+ ion. This energy shuffling is facilitated by a local defect that has been neglected in previous modeling work. Including this defect allows for a quantitative prediction of the relative time-averaged populations of the Eu3+ ion's D-5(0) and D-5(1) states. Extracting, from experimental results, …
Quantum Capacitance Investigation Of Different Tas2 Polymorphs For Energy Storage Applications – First Principles Study,
2022
American University in Cairo
Quantum Capacitance Investigation Of Different Tas2 Polymorphs For Energy Storage Applications – First Principles Study, Mahmoud Elattar
Theses and Dissertations
Energy is an essential requirement, which has a growing demand due to the growth of population and the world transformation into electronic. More than 70% of energy resources are fossil-fuel based which has an environmental impact due to the CO2 emissions. Energy hubs for Fossil-fuel to electric energy conversion, controlled CO2 emissions processing units, and energy storage system are key factors for a smooth transition to green energy without lack of energy supplies, where electrical energy storage systems (ESS) are key enablers to achieve that. One of the effective components which determines the ESS efficiency is the electrode …
Direct Observation Of Ferroelectric Switching In Two-Dimensional Mos2,
2022
University of Nebraska - Lincoln
Direct Observation Of Ferroelectric Switching In Two-Dimensional Mos2, A. Lipatov, P. Chaudhary, Z. Guan, H. Lu, G. Li, O. Crégut, K. D. Dorkenoo, R. Proksch, D.-F. Shao, E. Y. Tsymbal, J. Íñiguez, A. Sinitskii, A. Gruverman
Evgeny Tsymbal Publications
No abstract provided.
Tunneling Magnetoresistance In Noncollinear Antiferromagnetic Tunnel Junctions,
2022
University of Nebraska - Lincoln
Tunneling Magnetoresistance In Noncollinear Antiferromagnetic Tunnel Junctions, J. Dong, X. Li, G. Gurung, M. Zhu, P. Zhang, F. Zheng, E. Y. Tsymbal, J. Zhang
Evgeny Tsymbal Publications
Antiferromagnetic (AFM) spintronics has emerged as a subfield of spintronics driven by the advantages of antiferromagnets producing no stray fields and exhibiting ultrafast magnetization dynamics. The efficient method to detect an AFM order parameter, known as the Néel vector, by electric means is critical to realize concepts of AFM spintronics. Here, we demonstrate that noncollinear AFM metals, such as Mn3Sn, exhibit a momentum dependent spin polarization which can be exploited in AFM tunnel junctions to detect the Néel vector. Using first-principles calculations, we predict a tunneling magnetoresistance (TMR) effect as high as 300% in AFM tunnel junctions with …
Oxide Two-Dimensional Electron Gas With High Mobility At Room-Temperature,
2022
University of Nebraska - Lincoln
Oxide Two-Dimensional Electron Gas With High Mobility At Room-Temperature, K. Eom, H. Paik, J. Seo, N. Campbell, E. Y. Tsymbal, S. H. Oh, M. Rzchowski, D. G. Schlom, C.-B. Eom
Evgeny Tsymbal Publications
No abstract provided.
Tilted Spin Current Generated By The Collinear Antiferromagnet Ruo2,
2022
University of Nebraska - Lincoln
Tilted Spin Current Generated By The Collinear Antiferromagnet Ruo2, A. Bose, N. J. Schreiber, R. Jain, D.-F. Shao, H. P. Nair, J. Sun, X. S. Zhang, D. A. Muller, D. A. Muller, E. Y. Tsymbal, D. G. Schlom, D. C. Ralph
Evgeny Tsymbal Publications
No abstract provided.
Electronic Reconstruction At The Polar (111)-Oriented Oxide Interface,
2022
University of Nebraska - Lincoln
Electronic Reconstruction At The Polar (111)-Oriented Oxide Interface, S. Ryu, H. Zhou, T. R. Paudel, N. Campbell, J. Podkaminer, C. W. Bark, T. Hernandez, D. D. Fong, Y. Zhang, L. Xie, X. Q. Pan, E. Y. Tsymbal, M. S. Rzchowski, And C. B. Eom
Evgeny Tsymbal Publications
No abstract provided.
Ferroelectric Control Of Magnetic Skyrmions In Two-Dimensional Van Der Waals Heterostructures,
2022
University of Nebraska - Lincoln
Ferroelectric Control Of Magnetic Skyrmions In Two-Dimensional Van Der Waals Heterostructures, K. Huang, D.-F. Shao, E. Y. Tsymbal
Evgeny Tsymbal Publications
No abstract provided.
Generally Covariant Theory Of Multipole Moment Conserving Quasiparticles,
2022
University of New Hampshire
Generally Covariant Theory Of Multipole Moment Conserving Quasiparticles, Gavin Eric Riley
Honors Theses and Capstones
This report represents the creation of a field theory which is capable of describing quasiparticle excitations that preserve 2^k -pole moments. These quasiparticles exhibit certain ’semidynamic’ properties such as individual particle immobility but free movement of bound 2^L-tuples. We provide a review of work done on dipole conserving fractons and their dynamics [1] and expand upon it to describe higher moment conserving systems with global quadratic (and higher) phase symmetry. This requires the selection of the temporal and spatial directions. The selection of a temporal direction is done with a foliation defined by an anisotropic scaling of space and time, …
Superfluid Spin Transistor,
2022
University of Nebraska - Lincoln
Superfluid Spin Transistor, Edward Schwartz, Bo Li, Alexey Kovalev
Alexey Kovalev Papers
We propose to use the Hall response of topological defects, such as merons and antimerons, to spin currents in two-dimensional magnetic insulator with in-plane anisotropy for identification of the Berezinskii-Kosterlitz-Thouless (BKT) transition in a transistorlike geometry. Our numerical results relying on a combination of Monte Carlo and spin dynamics simulations show transition from spin superfluidity to conventional spin transport, accompanied by the universal jump of the spin stiffness and exponential growth of the transverse vorticity current. We propose a superfluid spin transistor in which the spin and vorticity currents are modulated by changes in density of free topological defects, e.g., …
Periodic Trends In The Infrared And Optical Absorption Spectra Of Metal Chalcogenide Clusters,
2022
Virginia Commonwealth University
Periodic Trends In The Infrared And Optical Absorption Spectra Of Metal Chalcogenide Clusters, Alain Ward
Theses and Dissertations
We have investigated the Optical absorption, Infrared spectra, Binding Energies, and various other cluster properties to determine the existence of periodic trend for Transition Metal Chalcogenide Clusters ligated with CO ligands. We were motivated to answer the question of whether periodic behavior can be observed in properties of octahedral metal-chalcogenide clusters. We have used the Amsterdam Density Functional code to calculate the electronic structure of Transition Metal Chalcogenide Clusters using gradient-corrected density functional theory. We determined the existence of several periodic trends in properties of octahedral Transition Metal Chalcogenide Clusters TM6Se8(CO)6. To investigate these …
Understanding The Degradation Mechanism In Methyl Ammonium Lead Halide Perovskite And Black Phosphorene Via Electrical Transport Study,
2022
University of Kentucky
Understanding The Degradation Mechanism In Methyl Ammonium Lead Halide Perovskite And Black Phosphorene Via Electrical Transport Study, Huda Saleh Aljeailan
Theses and Dissertations--Physics and Astronomy
This work seeks to understand the degradation mechanism of technically important material systems such as black phosphorene (BP), arsenic phosphorene (AsP) and Methyl ammonium lead iodide (CH3NH3PbI3) perovskite. Degradation studies were conducted by studying the in-situ electrical transport properties (resistance and thermoelectric power (TEP)) of these materials in vacuum (under annealed condition) and after exposure to the ambient air.
BP and both exhibited p-type semiconducting (positive TEP) behavior under annealed conditions and the changes in their transport properties upon exposure to ambient air can be explained as due to the charge transfer between the …
A Materials Study Of Topological Insulators And Two-Dimensional Ferromagnets,
2022
University of Pennsylvania
A Materials Study Of Topological Insulators And Two-Dimensional Ferromagnets, Sarah Friedensen
Publicly Accessible Penn Dissertations
Topological insulators and two-dimensional ferromagnetic materials are novel phases with wideranging applications including quantum computing, spintronics, and other advanced electronic devices with the potential for ultrathin and ultralow-power wearables. TEM, AFM, EDS, Ramanspectroscopy, and low-temperature transport measurement are used to characterize an unusual superconducting alloy formed between palladium and bismuth selenide under low-temperature annealing. TEM, AFM, and EDS are used to perform a materials study of metallic nickel and niobium annealed with Bi2Se3 under similar conditions, with the conclusion that Ni reacts to form a diffuse layer within Bi2Se3 flakes that travels along edges and line defects, and Nb does …
Characterization And Coherent Spin Selective Manipulation Of Quantum Dot Energy Levels,
2022
West Virginia University
Characterization And Coherent Spin Selective Manipulation Of Quantum Dot Energy Levels, Tristan Anthony Wilkinson
Graduate Theses, Dissertations, and Problem Reports
Semiconductor quantum dots (QDs) are promising candidates to fulfill a wide range of applications in real-world quantum computing, communication, and networks. Their excellent optical properties such as high brightness, single-photon purity, and narrow linewidths show potential utility in many areas. In order to realize long term goals of integration into complex and scalable quantum information systems, many current challenges must be overcome. One of these challenges is accomplishment of all necessary computing operations within a QD, which might be enabled by coherent manipulation of single QD energy level structures. In the realm of scalability for quantum devices, a way to …
Charge Dynamics Of Inas Quantum Dots Under Resonant And Above-Band Excitation,
2022
West Virginia University
Charge Dynamics Of Inas Quantum Dots Under Resonant And Above-Band Excitation, Gary R. Lander Jr
Graduate Theses, Dissertations, and Problem Reports
Research involving light-matter interactions in semiconductor nanostructures has been an interesting topic of investigation for decades. Many systems have been studied for not only probing fundamental physics of the solid state, but also for direct development of technological advancements. Research regarding self-assembled, epitaxially grown quantum dots (QDs) has proven to be prominent in both regards. The development of a reliable, robust source for the production of quantum bits to be utilized in quantum information protocols is a leading venture in the world of condensed matter and solid-state physics. Fluorescence from resonantly driven QDs is a promising candidate for the production …
What Happens When Transition Metal Trichalcogenides Are Interfaced With Gold?,
2022
University of Nebraska–Lincoln
What Happens When Transition Metal Trichalcogenides Are Interfaced With Gold?, Archit Dhingra, Dmitri E. Nikonov, Alexey Lipatov, Alexander Sinitskii, Peter Dowben
Peter Dowben Publications
Transition metal trichalcogenides (TMTs) are two-dimensional (2D) systems with quasi-one-dimensional (quasi-1D) chains. These 2D materials are less susceptible to undesirable edge defects, which enhances their promise for low-dimensional optical and electronic device applications. However, so far, the performance of 2D devices based on TMTs has been hampered by contact-related issues. Therefore, in this review, a diligent effort has been made to both elucidate and summarize the interfacial interactions between gold and various TMTs, namely, In4Se3, TiS3, ZrS3, HfS3, and HfSe3. X-ray photoemission spectroscopy data, supported by the results …
Development And Characterization Of Germanium Detectors For Searching Rare-Event Physics,
2022
University of South Dakota
Development And Characterization Of Germanium Detectors For Searching Rare-Event Physics, Rajendra Panth
Dissertations and Theses
High-purity germanium (HPGe) detector has an excellent energy resolution and low-energy detection threshold ideal for searching rare-event physics such as dark matter and neutrinoless double beta decay searches. Understanding the electrical contact properties and the Ge detector properties is key to enhancing the use of Ge detectors for a wide range of applications. Amorphous Ge (a-Ge) is one of the passivation materials used to passivate Ge detectors, which also provides the barrier height to the charge injection. Several a-Ge contact Ge detectors were fabricated and tested at the University of South Dakota (USD) and Max-Planck-Institut (MPI) für Physik in Munich …
Infrared Dielectric Functions And Brillouin Zone Center Phonons Of Α-Ga2O3 Compared To Α-Al2O3,
2022
University of Nebraska-Lincoln
Infrared Dielectric Functions And Brillouin Zone Center Phonons Of Α-Ga2O3 Compared To Α-Al2O3, Megan Stokey, Rafal Korlacki, Matthew J. Hilfiker, Sean Knight, Steffen Richter, Vanya Darakchieva, Riena Jinno, Yongjin Cho, Huili Grace Xing, Debdeep Jena, Yuichi Oshima, Kamruzzaman Khan, Elaheh Ahmadi, Mathias Schubert
Faculty Publications from the Department of Electrical and Computer Engineering
We determine the anisotropic dielectric functions of rhombohedral α-Ga2O3 by far-infrared and infrared generalized spectroscopic ellipsometry and derive all transverse optical and longitudinal optical phonon mode frequencies and broadening parameters. We also determine the high-frequency and static dielectric constants. We perform density functional theory computations and determine the phonon dispersion for all branches in the Brillouin zone, and we derive all phonon mode parameters at the Brillouin zone center including Raman-active, infrared-active, and silent modes. Excellent agreement is obtained between our experimental and computation results as well as among all previously reported partial information from experiment …