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 …
Imaging Based Beam Steering For Optical Communication And Lidar Applications,
2022
University of Central Florida
Imaging Based Beam Steering For Optical Communication And Lidar Applications, Sajad Saghaye Polkoo
Electronic Theses and Dissertations, 2020-2023
Optical beam steering is a key component in any application that requires dynamic (i.e. realtime control) of beam propagation through free-space. Example applications include remote sensing, spectroscopy, laser machining, targeting, Lidar, optical wireless communications (OWC) and more. The pointing control requirements for many of these applications can be met by traditional mechanical steering techniques; however, these solutions tend to be bulky, slow, expensive, power hungry and prone to mechanical failures leading to short component lifetimes. Two emerging applications, Lidar imaging and OWC, truly need improved beam-steering capabilities to flourish and support the advancement of self-driving cars or relieve the congestion …
Characterization Of Nanoparticles Using Inductively-Coupled Plasma Mass Spectrometry,
2022
Missouri State University
Characterization Of Nanoparticles Using Inductively-Coupled Plasma Mass Spectrometry, Jabez D. Campbell
Graduate Theses/Dissertations
Nanomaterials are a relatively new class of materials that have many applications which span a wide host of fields from medical products to consumer products. The possible compositions and forms of nanomaterials are just as varied as the applications. Therefore, a versatile characterization method is needed for researchers and regulators alike to ensure nanomaterials are properly used. Single Particle Inductively Coupled Plasma Mass Spectrometry (SP-ICP-MS) is a functional method that could fill the characterization need in the nanomaterial research field. Using data from both SP-ICP-MS tests and data from literature established characterization methods, the viability of making SP-ICP-MS the standard …
Measuring The Diphoton Production From Higgs Boson Decays And In Association With Heavy Flavor Jets,
2022
Northern Illinois University
Measuring The Diphoton Production From Higgs Boson Decays And In Association With Heavy Flavor Jets, Brianna Lynn Dwyer
Graduate Research Theses & Dissertations
In this dissertation, two important measurements are presented related to diphoton production, the differential cross-section measurement of the Higgs boson in the diphoton decay channel as well as a measurement on inclusive diphoton production with associated heavy-flavor jets. Selections between the two analyses are complimentary, making them a natural pairing in the context of this dissertation. The cross-section measurement is performed in a fiducial region of phase space to closely matches experimental selections. This allows for a largely model-independent measurement, providing a meticulous test of the Standard Model as well as other theoretical predictions. The production of diphoton + heavy-flavor …
Search For Charged Higgs Bosons In The Tau+Nu Final State With 139 Inverse Fb Of Pp Collision Data At Sqrt(S)=13 Tev With The Atlas Experiment,
2022
Northern Illinois University
Search For Charged Higgs Bosons In The Tau+Nu Final State With 139 Inverse Fb Of Pp Collision Data At Sqrt(S)=13 Tev With The Atlas Experiment, Elliot Wesley Parrish
Graduate Research Theses & Dissertations
This dissertation uses 139 inverse fb of pp collision data collected at a center of mass energy of sqrt(s)=13 TeV by the ATLAS detector to search for charged Higgs bosons decaying to a tau lepton and a neutrino in association with a top quark. Two subchannels are defined based on the leptonic decay (tau+lepton) or hadronic decay (tau+jets) of the associated top quark. Parameterized Neural Networks are investigated and optimized to improve signal separation from background in both subchannels across a wide charged Higgs boson mass range of 80 GeV to 3000 GeV. Expected exclusion limits at 95% confidence on …
Studies Of Vector Boson Scattering In The Semileptonic Zv Channel With The Cms Detector At √S = 13 Tev,
2022
Northern Illinois University
Studies Of Vector Boson Scattering In The Semileptonic Zv Channel With The Cms Detector At √S = 13 Tev, Ramanpreet Singh
Graduate Research Theses & Dissertations
This dissertation reports on the search for the vector boson scattering (VBS) in semileptonicZV channel, where the Z boson decays to a pair of leptons (electrons or muons), and the other vector boson V (either W or Z) decays hadronically to a pair of jets, in association of two large pseudorapidity jets i.e. ZVjj → l+l−jjjj, l = e or μ. The search used 137 fb−1 of proton-proton collision data collected by the Compact Muon Solenoid (CMS) experiment at the Large Hadron Collider (LHC) with center-of-mass energy (√s) of 13 TeV from 2016 to 2018. VBS is a key process …
Photonics Of Time-Varying Media,
2022
CUNY Advanced Science Research Center
Photonics Of Time-Varying Media, Emanuele Galiffi, Romain Tirole, Shixiong Yin, Huanan Li, Stefano Vezzoli, Paloma A. Huidobro, Mário G. Silveirinha, Riccardo Sapienza, Andrea Alù, J. B. Pendry
Advanced Science Research Center
Time-varying media have recently emerged as a new paradigm for wave manipulation, due to the synergy between the discovery of highly nonlinear materials, such as epsilon-near-zero materials, and the quest for wave applications, such as magnet-free nonreciprocity, multimode light shaping, and ultrafast switching. In this review, we provide a comprehensive discussion of the recent progress achieved with photonic metamaterials whose properties stem from their modulation in time. We review the basic concepts underpinning temporal switching and its relation with spatial scattering and deploy the resulting insight to review photonic time-crystals and their emergent research avenues, such as topological and non-Hermitian …
Moiré-Driven Topological Transitions And Extremeanisotropy In Elastic Metasurfaces,
2022
CUNY Advanced Science Research Center
Moiré-Driven Topological Transitions And Extremeanisotropy In Elastic Metasurfaces, Simon Yves, Matheus Inguaggiato Nora Nora Rosa, Mohit Gupta, Massimo Ruzzene, Andrea Alù
Advanced Science Research Center
The twist angle between a pair of stacked 2D materials has been recently shown to control remarkable phenomena, including the emergence of flat-band superconductivity in twisted graphene bilayers, of higher-order topological phases in twisted moiré superlattices, and of topological polaritons in twisted hyperbolic metasurfaces. These discoveries, at the foundations of the emergent field of twistronics, have so far been mostly limited to explorations in atomically thin condensed matter and photonic systems, with limitations on the degree of control over geometry and twist angle, and inherent challenges in the fabrication of carefully engineered stacked multilayers. Here, this work extends twistronics to …
Application Of Image Processing Programs In Color Analysis Of Wood Photodegradation,
2022
Ateneo de Manila University
Application Of Image Processing Programs In Color Analysis Of Wood Photodegradation, Gabriel Joseph D. Plata, Ramon M. Delos Santos
Physics Faculty Publications
In general, polymer photodegradation is an important aspect of polymer science that is of great interest to chemistry, materials science, biology, and physics students who engage in this field of research. Wood consists of three main polymers, which makes it a good candidate for such photodegradation studies. Aside from structural changes based on chemical analysis, color change assessment can also be employed to check any extent of degradation on wood without the need for sophisticated analytical equipment. This study presents the application of two image processing programs in color analysis of wood photodegradation: ImageJ and Colormath library, which are Java-based …
Coupled Dynamics Of Spin Qubits In Optical Dipole Microtraps: Application To The Error Analysis Of A Rydberg-Blockade Gate,
2022
Old Dominion University
Coupled Dynamics Of Spin Qubits In Optical Dipole Microtraps: Application To The Error Analysis Of A Rydberg-Blockade Gate, L. V. Gerasimov, R. R. Yusupov, A. D. Moiseevsky, I. Vybornyi, K. S. Tikhonov, S. P. Kulik, S. S. Straupe, Charles I. Sukenik, D. V. Kupriyanov
Physics Faculty Publications
Single atoms in dipole microtraps or optical tweezers have recently become a promising platform for quantum computing and simulation. Here we report a detailed theoretical analysis of the physics underlying an implementation of a Rydberg two-qubit gate in such a system—a cornerstone protocol in quantum computing with single atoms. We focus on a blockade-type entangling gate and consider various decoherence processes limiting its performance in a real system. We provide numerical estimates for the limits on fidelity of the maximally entangled states and predict the full process matrix corresponding to the noisy two-qubit gate. We consider different excitation geometries and …
Ring Bose–Einstein Condensate Atomtronic Rotation Sensor,
2022
Georgia Southern University
Ring Bose–Einstein Condensate Atomtronic Rotation Sensor, Oluwatobi I. Adeniji
College of Graduate Studies: Theses & Dissertations
We propose a design for an atomtronic rotation sensor consisting of an array of Bose– Einstein condensates (BECs) confined in a double–target–array potential. The purpose of the sensor is to measure the rotation speed, ΩR, of the sensor’s rest frame with respect to the “fixed stars.” The atomtronic system consists of an ultracold gas of sodium atoms compressed, using laser light, into a thin horizontal sheet and subjected to a double–target– array potential within the horizontal plane. A “target” BEC consists of a disk–shaped condensate surrounded by a concentric ring–shaped condensate. A “double–target” BEC is two adjacent target …
Angular Distribution Of Electron-Helium Scattering In The Presence Of A 1.17 Ev Laser Field,
2022
University of Kentucky
Angular Distribution Of Electron-Helium Scattering In The Presence Of A 1.17 Ev Laser Field, Brian N. Kim
Theses and Dissertations--Physics and Astronomy
We have measured relative differential cross sections for 350 eV electrons scattered by a helium target in the presence of 1.17 eV photons from an Nd:YAG laser. We report an angular distribution of free-free electrons that were scattered elastically at angles between 15o and 80o and of free-free electrons that underwent the process of electron-impact excitation of helium to its unresolved (1s2s)1S and (1s2p)1P excited states at angles between 1o and 80o. Our experiments test the momentum transfer dependence and the relationship between elastic and inelastic scattering in the Kroll-Watson approximation. …
Splashing Of Large Helium Nanodroplets Upon Surface Collisions,
2021
University of Innsbruck
Splashing Of Large Helium Nanodroplets Upon Surface Collisions, Paul Martini, Simon Albertini, Felix Laimer, Miriam Meyer, Michael Gatchell, Olof E. Echt, Fabio Zappa, Paul Scheier
Faculty Publications
In the present work we observe that helium nanodroplets colliding with surfaces can exhibit splashing in a way that is analogous to classical liquids. We use transmission electron microscopy and mass spectrometry to demonstrate that neutral and ionic dopants embedded in the droplets are efficiently backscattered in such events. High abundances of weakly bound He-tagged ions of both polarities indicate a gentle extraction mechanism of these ions from the droplets upon collision with a solid surface. This backscattering process is observed for dopant particles with masses up to 400 kilodaltons, indicating an unexpected mechanism that effectively lowers deposition rates of …
Intracavity Phase Interferometry Based Fiber Sensors,
2021
University of New Mexico - Main Campus
Intracavity Phase Interferometry Based Fiber Sensors, Luke Jameson Horstman
Optical Science and Engineering ETDs
Intracavity Phase Interferometry (IPI) is a detection technique that exploits the inherent sensitivity of a laser's frequency to the parameters of its cavity. Intracavity interferometry is orders of magnitude more sensitive than its extracavity alternatives. This dissertation improves on previous free-space proof-of-concept designs. By implementing the technique in fiber optics, using optical parametric oscillation, and investigating non-Hermitian quantum mechanics and dispersion tailoring enhancement techniques, IPI has become more applicable and sensitive. Ring and linear IPI configurations were realized in this work, both operating as bidirectional fiber optical parametric oscillators. The benefit of using externally pumped synchronous optical parametric oscillation is …
Study Of The Geometric Structure Of Low-Atomic Copper Clusters Using Computer Simulation,
2021
Ferghana Polytechnic Institute
Study Of The Geometric Structure Of Low-Atomic Copper Clusters Using Computer Simulation, Nodirbek Ikromjonovich Ibrokhimov
Scientific-technical journal
In this work, we investigated the geometric structure of small neutral copper clusters with low energy using the MD (Molecular Dynamics) method. When calculating the processes of interatomic interaction, we used a potential EAM (Embedded-atom method). A computer model of Cun (n = 2-13) clusters has been created. The geometric shapes of the Cu2, Cu3, Cu4, Cu5, Cu6, Cu7, Cu8, Cu9, Cu10, Cu11, Cu12, and Cu13 clusters have been studied and the structural parameters (Cu-Cu bond …
Effects Of Anharmonicity In A Dual-Sagnac Interferometer,
2021
Georgia Southern University
Effects Of Anharmonicity In A Dual-Sagnac Interferometer, Stephen Thomas
Honors College Theses
A recent experiment implemented a dual Sagnac atom interferometer (AI) for rotation sensing using a Bose-Einstein condensate (BEC) confined in a TOP-trap potential. The BEC is split twice by laser light to create two pairs of counter-orbiting clouds in a lowest-order harmonic potential with each pair acting as a separate Sagnac interferometer. After one orbit the two overlapping cloud pairs are split again and the interference patterns are inferred from the population of atoms in the zero-momentum state. We have simulated the impact of the presence of anharmonic terms in the potential on the performance of the AI as measured …
Accurate Flux Calibration Of Gw170817: Is The X-Ray Counterpart On The Rise?,
2021
University of Maryland
Accurate Flux Calibration Of Gw170817: Is The X-Ray Counterpart On The Rise?, E. Troja, B. O'Connor, G. Ryan, L. Piro, R. Ricci, B. Zhang, T. Piran, G. Bruni, S. B. Cenko, H. Van Eerten
Physics & Astronomy Faculty Research
X-ray emission from the gravitational wave transient GW170817 is well described as non-thermal afterglow radiation produced by a structured relativistic jet viewed off-axis. We show that the X-ray counterpart continues to be detected at 3.3 years after the merger. Such long-lasting signal is not a prediction of the earlier jet models characterized by a narrow jet core and a viewing angle ≈20 deg, and is spurring a renewed interest in the origin of the X-ray emission. We present a comprehensive analysis of the X-ray dataset aimed at clarifying existing discrepancies in the literature, and in particular the presence of an …
Voltage Controlled Néel Vector Rotation In Zero Magnetic Field,
2021
University of Nebraska–Lincoln
Voltage Controlled Néel Vector Rotation In Zero Magnetic Field, Ather Mahmood, Will Echtenkamp, Mike Street, Jun Lei Wang, Shi Cao, Takashi Komesu, Peter Dowben, Pratyush Buragohain, Haidong Lu, Alexei Gruverman, Arun Parthasarathy, Shaloo Rakheja, Christian Binek
Peter Dowben Publications
Multi-functional thin films of boron (B) doped Cr2O3 exhibit voltage-controlled and nonvolatile Néel vector reorientation in the absence of an applied magnetic field, H. Toggling of antiferromagnetic states is demonstrated in prototype device structures at CMOS compatible temperatures between 300 and 400 K. The boundary magnetization associated with the Néel vector orientation serves as state variable which is read via magnetoresistive detection in a Pt Hall bar adjacent to the B:Cr2O3 film. Switching of the Hall voltage between zero and non-zero values implies Néel vector rotation by 90 degrees. Combined magnetometry, spin resolved inverse …
Quantum State Tomography Of Molecules By Ultrafast Diffraction,
2021
Peking University
Quantum State Tomography Of Molecules By Ultrafast Diffraction, Ming Zhang, Shuqiao Zhang, Yanwei Xiong, Hankai Zhang, Anatoly A. Ischenko, Oriol Vendrell, Xiaolong Dong, Xiangxu Mu, Martin Centurion, Haitan Xu, R. J.Dwayne Miller, Zheng Li
Martin Centurion Publications
Ultrafast electron diffraction and time-resolved serial crystallography are the basis of the ongoing revolution in capturing at the atomic level of detail the structural dynamics of molecules. However, most experiments capture only the probability density of the nuclear wavepackets to determine the time-dependent molecular structures, while the full quantum state has not been accessed. Here, we introduce a framework for the preparation and ultrafast coherent diffraction from rotational wave packets of molecules, and we establish a new variant of quantum state tomography for ultrafast electron diffraction to characterize the molecular quantum states. The ability to reconstruct the density matrix, which …
Sigesn Light-Emitting Devices: From Optical To Electrical Injection,
2021
University of Arkansas, Fayetteville
Sigesn Light-Emitting Devices: From Optical To Electrical Injection, Yiyin Zhou
Graduate Theses and Dissertations
Si photonics is a fast-developing technology that impacts many applications such as data centers, 5G, Lidar, and biological/chemical sensing. One of the merits of Si photonics is to integrate electronic and photonic components on a single chip to form a complex functional system that features compact, low-cost, high-performance, and reliability. Among all building blocks, the monolithic integration of lasers on Si encountered substantial challenges. Si and Ge, conventional epitaxial material on Si, are incompetent for light emission due to the indirect bandgap. The current solution compromises the hybrid integration of III-V lasers, which requires growing on separate smaller size substrates …
