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Full-Text Articles in Condensed Matter Physics

Lesker Pvd75 E-Beam/Thermal Evaporator (Pvd-02) Standard Operating Procedure, David S. Barth, Jason A. Röhr Jan 2023

Lesker Pvd75 E-Beam/Thermal Evaporator (Pvd-02) Standard Operating Procedure, David S. Barth, Jason A. Röhr

Standard Operating Procedures

Standard Operating Procedure for the Lesker PVD75 E-beam/Thermal Evaporator (PVD-02) located at the Quattrone Nanofabrication Facility within the Singh Center for Nanotechnology at the University of Pennsylvania


Structural And Magneto Conductivity Studies Of Nio/Smba2cu3o7-Δ Superconducting Composite, Hadi Basma, Sajida Rmeid, Ramadan Awad, Mohammed Said Dec 2022

Structural And Magneto Conductivity Studies Of Nio/Smba2cu3o7-Δ Superconducting Composite, Hadi Basma, Sajida Rmeid, Ramadan Awad, Mohammed Said

BAU Journal - Science and Technology

In this work, we investigate the effect of NiO nanoparticles' addition on the structure, superconductivity, and magneto conductivity for the SmBa2Cu3O7-δ phase. Composite nano/superconductor of (NiO)x/SmBa2Cu3O7-δ (0.00≤x≤0.12 wt.%) were prepared by conventional solid-state reaction technique and characterized by X-ray powder diffraction (XRD) and scanning electron microscopy (SEM). The orthorhombic structure was maintained whereas the lattice parameters showed unsystematic variations with the NiO nanoparticles addition. The superconducting transition temperature Tc, determined from electrical resistivity measurements, showed an enhancement with x up to 0.04wt.% followed by a reduction …


Imaging Normal Fluid Flow In He Ii With Neutrons And Lasers — A New Application Of Neutron Beams For Studies Of Turbulence, Xin Wen Dec 2022

Imaging Normal Fluid Flow In He Ii With Neutrons And Lasers — A New Application Of Neutron Beams For Studies Of Turbulence, Xin Wen

Doctoral Dissertations

Turbulence is ubiquitous in life —from biology to astrophysics. The best direct numeric simulations (DNS) have only been benchmarked against low resolution, time-averaged experimental configurations—partly because of limitations in computing power. With time, computing power has greatly increased, so there is need for higher quality data of turbulent flow. In this dissertation, we explore a solution that enables quantitative visualization measurement of the velocity field in liquid helium, which has the potential of breaking new ground for high Reynolds number turbulence research and model testing.

Our technique involves creation of clouds of molecular tracers using 3He-neutron absorption reaction in liquid …


Raman Scattering Measurements And Analyses Of Gan Thin Films Grown On Zno Substrates By Metalorganic Chemical Vapor Deposition, Zane Mcdaniel, Zhe Chuan Feng, Kevin Stokes Nov 2022

Raman Scattering Measurements And Analyses Of Gan Thin Films Grown On Zno Substrates By Metalorganic Chemical Vapor Deposition, Zane Mcdaniel, Zhe Chuan Feng, Kevin Stokes

Symposium of Student Scholars

Metalorganic chemical vapor deposition (MOCVD) is a popularly used method of growing thin films of GaN on ZnO (GZ) substrates, which pair well due to their structural and characteristic similarities. In this research, optical characterization of the surface quality of GZ sample films is measured by analyzing Raman scattering (RS) using a Renishaw inVia spectrometer fitted with a 532nm laser. Samples were grown in an improved double injection block rotating disc reactor. Multiple samples' spectra show broad peaks that correspond with the E2 (high) and A1 (LO) branches of GaN, and nicely fitted curves are observed for the characteristic E2 …


Exploring Cathodoluminescence Evident Features Of Tungsten Disulfide, Molybdenum Disulfide, And Tungsten-Sulfide-Selenide, Nathan Mayer Nov 2022

Exploring Cathodoluminescence Evident Features Of Tungsten Disulfide, Molybdenum Disulfide, And Tungsten-Sulfide-Selenide, Nathan Mayer

Undergraduate Theses

Cathodoluminescence (CL) microscopy can be used to characterize the quantum optical behaviors of two-dimensional nanostructures. To investigate this behavior, we mounted flakes of tungsten disulfide (WS2), molybdenum disulfide (MoS2), and tungsten-sulfide-selenide Janus structures (WSSe) on a SiO2 substrate and analyzed these samples under both high vacuum and low H2O vacuum conditions using a scanning electron microscope. We then captured CL and secondary-electron images of the samples at multiple electron-beam energies and currents (5 keV to 30 keV, and 0.5 nA to 5 nA, respectively). We used a range of beam currents and …


Physics 516: Electromagnetic Phenomena (Spring 2023), Philip C. Nelson Nov 2022

Physics 516: Electromagnetic Phenomena (Spring 2023), Philip C. Nelson

Department of Physics Papers

These course notes are made publicly available in the hope that they will be useful. All reports of errata will be gratefully received. I will also be glad to hear from anyone who reads them, whether or not you find errors: pcn@upenn.edu.


An Interactive Simulation And Visualization Tool For Conventional And Aberration-Corrected Transmission Electron Microscopy, Xingzhong Li Nov 2022

An Interactive Simulation And Visualization Tool For Conventional And Aberration-Corrected Transmission Electron Microscopy, Xingzhong Li

Faculty Publications from Nebraska Center for Materials and Nanoscience

Contrast transfer function (CTF) is a vital function in transmission electron microscopy (TEM). It expresses to what extent amplitudes converted from the phase changes of the diffracted waves contribute to the TEM image, including the effects of lens aberrations. Simulation is very helpful to understand the application of the function thoroughly. In this work, we develop the CTFscope as a component in the Landyne software suite, to calculate the CTF with temporal and spatial dumping envelopes for conventional TEM and to extend it to various aberrations (up to fifth order) for aberration-corrected (AC)- TEM. It also includes effects on the …


Symmetry Breaking Effects In Low-Dimensional Quantum Systems, Ke Wang Oct 2022

Symmetry Breaking Effects In Low-Dimensional Quantum Systems, Ke Wang

Doctoral Dissertations

Quantum criticality in low-dimensional quantum systems is known to host exotic behaviors. In quantum one-dimension (1D), the emerging conformal group contains infinite generators, and conformal techniques, e.g., operator product expansion, give accurate and universal descriptions of underlying systems. In quantum two-dimension (2D), the electronic interaction causes singular corrections to Fermi-liquids characteristics. Meanwhile, the Dirac fermions in topological 2D materials can greatly enrich emerging phenomena. In this thesis, we study the symmetry-breaking effects of low-dimensional quantum criticality. In 1D, we consider two cases: time-reversal symmetry (TRS) breaking in the Majorana conformal field theory (CFT) and the absence of conformal symmetry in …


Anomalous Transport, Quasiperiodicity, And Measurement Induced Phase Transitions, Utkarsh Agrawal Oct 2022

Anomalous Transport, Quasiperiodicity, And Measurement Induced Phase Transitions, Utkarsh Agrawal

Doctoral Dissertations

With the advent of the noisy-intermediate scale quantum (NISQ) era quantum computers are increasingly becoming a reality of the near future. Though universal computation still seems daunting, a great part of the excitement is about using quantum simulators to solve fundamental problems in fields ranging from quantum gravity to quantum many-body systems. This so-called second quantum revolution rests on two pillars. First, the ability to have precise control over experimental degrees of freedom is crucial for the realization of NISQ devices. Significant progress in the control and manipulation of qubits, atoms, and ions, as well as their interactions, has not …


Explorer 14 Magnetron Sputterer (Pvd-05) Standard Operating Procedure, Mohsen Azadi, Jason Alexander Röhr Oct 2022

Explorer 14 Magnetron Sputterer (Pvd-05) Standard Operating Procedure, Mohsen Azadi, Jason Alexander Röhr

Standard Operating Procedures

Standard Operating Procedure for the Explorer 14 Magnetron Sputterer (PVD-05) located at the Quattrone Nanofabrication Facility within the Singh Center for Nanotechnology at the University of Pennsylvania


Controlling Electro-Magnetic Functionality Of Ruthenates By Heterostructure Design, Zeeshan Ali Oct 2022

Controlling Electro-Magnetic Functionality Of Ruthenates By Heterostructure Design, Zeeshan Ali

LSU Doctoral Dissertations

Perovskite oxides (ABO3) show wide range of functionalities originating from interplay of structural, spin, charge, and orbital degrees of freedoms. The bulk perovskite structure could be controlled via conventional chemical substitution, though exploiting heterostructure engineering novel ground states could be observed which otherwise are absent in bulk. In this thesis, the interest is to explore the electro-magnetic phenomena as complex oxides are confined in heterostructures.

I first investigate electromagnetic properties of ultrathin epitaxial ruthenate: SrRuO3 (SRO); spatially confined between SrTiO3 (STO) i.e., STO5-SROn-STO5 with n = 1- and 2-unit cells. It …


Lesker Pvd75 E-Beam Evaporator (Pvd-04) Standard Operating Procedure, David J. Jones, Jason A. Röhr Oct 2022

Lesker Pvd75 E-Beam Evaporator (Pvd-04) Standard Operating Procedure, David J. Jones, Jason A. Röhr

Standard Operating Procedures

Standard Operating Procedure for the Lesker PVD75 E-beam Evaporator (PVD-04) located at the Quattrone Nanofabrication Facility within the Singh Center for Nanotechnology at the University of Pennsylvania


A Tem Study Of Fe3+X Co3-XTi2 (X = 0, 1, 2, 3) Intermetallic Alloys, Xingzhong Li, Anandakumar Sarella, B. Balasubramanian, Shah R. Valloppilly Oct 2022

A Tem Study Of Fe3+X Co3-XTi2 (X = 0, 1, 2, 3) Intermetallic Alloys, Xingzhong Li, Anandakumar Sarella, B. Balasubramanian, Shah R. Valloppilly

David Sellmyer Publications

A TEM study has been carried out on crystal structures in the rare-earth-free intermetallic alloys, Fe3+xCo3-xTi2 (x = 0, 1, 2, 3). These alloys have been demonstrated to have potentially high magnetic anisotropy. In these alloys, the main intermetallic compound was recently reported as a new hexagonal phase with a space group of P-6 m2. The present study reveals that the main compound belongs to Laves C14 variant surrounded by α-Fe type crystal as secondary phase in the Fe3+xCo3-xTi2 (x = 0, 1, 2, 3) alloys, in agreement with the …


Pressure-Induced Modifications To The Structural And Optoelectronic Properties Of 2d Hybrid Organic-Inorganic Perovskites, Jesse Ratte Sep 2022

Pressure-Induced Modifications To The Structural And Optoelectronic Properties Of 2d Hybrid Organic-Inorganic Perovskites, Jesse Ratte

Electronic Thesis and Dissertation Repository

Recently, 2D hybrid organic-inorganic perovskites (HOIP) have garnered lots of research interest for their applications in optoelectronic devices, especially in solar cells. The optoelectronic properties of 2D HOIPs have yet to be optimized for these applications. High external pressure is well known to induce structural modifications to 2D HOIPs, and thus modify their optoelectronic properties. Herein, we report a study of the effects of high pressure (HP) on the structures and optoelectronic properties of cyclohexane methylamine (CMA) lead iodide (CMA2PbI4) and the structures of N,N-dimethylphenylene-p-diammonium (DPDA) lead iodide (DPDAPbI4).

High pressure measurements of CMA2PbI4 were performed using Raman spectroscopy, Fourier-transform …


Resonant Plasmonic–Biomolecular Chiral Interactions In The Far-Ultraviolet: Enantiomeric Discrimination Of Sub-10 Nm Amino Acid Films, Tiago Ramos Leite, Lin Zschiedrich, Orhan Kizilkaya, Kevin M. Mcpeak Sep 2022

Resonant Plasmonic–Biomolecular Chiral Interactions In The Far-Ultraviolet: Enantiomeric Discrimination Of Sub-10 Nm Amino Acid Films, Tiago Ramos Leite, Lin Zschiedrich, Orhan Kizilkaya, Kevin M. Mcpeak

Faculty Publications

Resonant plasmonic–molecular chiral interactions are a promising route to enhanced biosensing. However, biomolecular optical activity primarily exists in the far-ultraviolet regime, posing significant challenges for spectral overlap with current nano-optical platforms. We demonstrate experimentally and computationally the enhanced chiral sensing of a resonant plasmonic–biomolecular system operating in the far-UV. We develop a full-wave model of biomolecular films on Al gammadion arrays using experimentally derived chirality parameters. Our calculations show that detectable enhancements in the chiroptical signals from small amounts of biomolecules are possible only when tight spectral overlap exists between the plasmonic and biomolecular chiral responses. We support this conclusion …


Electron Transport In Quantum Systems With Interaction, Sara Abedi Sep 2022

Electron Transport In Quantum Systems With Interaction, Sara Abedi

Dissertations, Theses, and Capstone Projects

No abstract provided.


Control Of Nonlinear Properties Of Van Der Waals Materials, Rezlind Bushati Sep 2022

Control Of Nonlinear Properties Of Van Der Waals Materials, Rezlind Bushati

Dissertations, Theses, and Capstone Projects

Van der Waals materials are a broad class of materials that exhibit unique optoelectronic properties. They provide a rich playground for which they can be integrated into current on-chip devices due to their nanometer-scale size, and be utilized for studying fundamental physics. Strong coupling of emitters to microcavities provides many opportunities for new exotic physics through the formation of hybrid quasi-particles exciton-polaritons. This thesis
focuses on exploring and enhancing nonlinearity of van der Waals materials through strongly coupling to microcavities. By taking advantage of the stacking order of TMDs, we show intense second-harmonic generation from bulk, centrosymmetric TMD systems. In …


Engineering Rare-Earth Based Color Centers In Wide Bandgap Semiconductors For Quantum And Nanoscale Applications, Gabriel I. López-Morales Sep 2022

Engineering Rare-Earth Based Color Centers In Wide Bandgap Semiconductors For Quantum And Nanoscale Applications, Gabriel I. López-Morales

Dissertations, Theses, and Capstone Projects

For many years, atomic point-defects have been readily used to tune the bulk properties of solid-state crystalline materials, for instance, through the inclusion of elemental impurities (doping) during growth, or post-processing treatments such as ion bombardment or high-energy irradiation. Such atomic point-defects introduce local ‘incompatible’ chemical interactions with the periodic atomic arrangement that makes up the crystal, resulting for example in localized electronic states due to dangling bonds or excess of electrons. When present in sufficient concentrations, the defects interact collectively to alter the overall bulk properties of the host material. In the low concentration limit, however, point-defects can serve …


Stability Of Two-Dimensional Magnetic Skyrmions, Amel Derras-Chouk Sep 2022

Stability Of Two-Dimensional Magnetic Skyrmions, Amel Derras-Chouk

Dissertations, Theses, and Capstone Projects

Magnetic skyrmions are whirls formed by magnetic moments in a crystal. They have attracted attention largely due to their topological protection, which provides an avenue for technology like next-generation memory storage. The idea of topologically protected solutions of a quantum field theory was originally proposed by Tony Skyrme when he developed a model to explain the stability of hadrons in particle physics. His work has extended far beyond his original intent to several areas of condensed matter physics. Here we focus on skyrmions in magnetic materials.

Skyrme's original theory modeled excitations which exist in three spatial dimensions, a requirement for …


Driven Dipolaritons In Van Der Waals Transition Metal Dichalcogenide Heterostructures: Properties And Applications, Patrick Serafin Sep 2022

Driven Dipolaritons In Van Der Waals Transition Metal Dichalcogenide Heterostructures: Properties And Applications, Patrick Serafin

Dissertations, Theses, and Capstone Projects

The need for advances in optical computation leads us toward the investigation of novel methods of re-routing light in optical circuits. The behavior and properties of electrically driven exciton-dipolaritons in van der Waals transition metal dichalcogenides are investigated as a platform for realizing working elements of a polaritronic transistor. In this work, we consider exciton-dipolaritons, which are three-way superposition of cavity photons, direct excitons, and indirect excitons in a bilayer semiconducting system embedded in an optical microcavity. We start by providing motivation for our study of polaritons and then survey the fundamental properties of exciton-dipolaritons. We also survey the basic …


Coupled Oscillators: Protein And Acoustics, Angelique N. Mcfarlane Aug 2022

Coupled Oscillators: Protein And Acoustics, Angelique N. Mcfarlane

Theses

This work encompassed three different vibrational energy transfer studies of coupled resonators (metal, topological, and microtubule comparison) inspired by the lattices of microtubules from regular and cancerous cells. COMSOL Multiphysics 5.4 was utilized to design the experiment. The simulation starts with an acoustic pressure study to examine the vibrational modes present in coupled cylinders, representing α-, β-tubulin heterodimers. The Metal Study consisted of 3 models (monomer, dimer, and trimer) to choose the correct height (40 mm) and mode (Mode 1) for study. The Topological Study was run to predict and understand how the lattice structure changes over a parametric sweep …


Physical Vapor Transport Growth Of Antiferromagnetic Crcl3 Flakes Down To Monolayer Thickness, Jia Wang, Zahra Ahmadi, David Lujan, Jeongheon Choe, Xiaoqin Li, Jeffrey E. Shield, Xia Hong Aug 2022

Physical Vapor Transport Growth Of Antiferromagnetic Crcl3 Flakes Down To Monolayer Thickness, Jia Wang, Zahra Ahmadi, David Lujan, Jeongheon Choe, Xiaoqin Li, Jeffrey E. Shield, Xia Hong

Faculty Publications, Department of Physics and Astronomy

The van der Waals magnets CrX3 (X = I, Br, and Cl) exhibit highly tunable magnetic properties and are promising candidates for developing novel two-dimensional (2D) magnetic devices such as magnetic tunnel junctions and spin tunneling transistors. Previous studies of CrCl3 have mainly focused on mechanically exfoliated samples. Controlled synthesis of high quality atomically thin flakes is critical for their technological implementation but has not been achieved to date. Here, we report the growth of large CrCl3 flakes with well-defined facets down to monolayer thickness (~0.6 nm) via the physical vapor transport technique. Long stripes of tri-layer samples …


Magnetic Skyrmions Unwrapped, Alexey Kovalev Aug 2022

Magnetic Skyrmions Unwrapped, Alexey Kovalev

Alexey Kovalev Papers

Experiments with chiral magnets may hold the key to a better understanding of fundamental aspects of transformations between different skyrmionic states, necessary for magnetic memory and logic applications to become a reality.

With the aim of developing computing devices that operate with low power dissipation, scientists have been pursuing the idea of encoding information in magnetic states. Specifically, skyrmions, which can be thought of as whirl-like states of magnetic moments, are promising candidates for this purpose. The advantage of skyrmions lies in their topological protection, a property implying that only a ‘global’ system modification can erase a skyrmion. Realizations of …


Quantum Computational Simulations For Condensed Matter Systems, Trevor Alan Keen Aug 2022

Quantum Computational Simulations For Condensed Matter Systems, Trevor Alan Keen

Doctoral Dissertations

In condensed matter physics, and especially in the study of strongly correlated electron systems, numerical simulation techniques are crucial to determine the properties of the system including interesting phases of matter that arise from electron-electron interactions. Many of these interesting phases of matter, including but not limited to Mott-insulating materials and possibly high-temperature superconducting systems, can be modeled by the Hubbard model. Although it is one of the simplest models to include electron-electron interactions, it cannot be solved analytically in more than one dimension and thus numerical techniques must be employed. Although there have been great strides in classical numerical …


Studying Electron Dynamics For Quantum Materials With Real Space Resolution: A Wannier Orbital Approach To Spectroscopy Using High-Performance Supercomputers, Casey J. Eichstaedt Aug 2022

Studying Electron Dynamics For Quantum Materials With Real Space Resolution: A Wannier Orbital Approach To Spectroscopy Using High-Performance Supercomputers, Casey J. Eichstaedt

Doctoral Dissertations

Quantum materials have a promising future for energy and security applications which will lay the bedrock for material science research for decades to follow. Partic- ularly, ‘one-dimensional’ Mott-insulating cuprates such as SrCuO 2 and (Ca)Sr 2 CuO 3 have been deemed to fall under a ‘fractionalization’ paradigm in which the electrons disintegrate into bosonic collective excitations of their fundamental constituents— spin, charge, and ‘orbital’ degrees of freedom— due to the anisotropic crystalline structure, deeming them outside the band theory of solids. Here, I provide ab initio theory for the ‘one-dimensional’ cuprates SrCuO 2 and (Ca)Sr 2 CuO 3 using no …


Semi-Classical Theories Of Quantum Magnets, Hao Zhang Aug 2022

Semi-Classical Theories Of Quantum Magnets, Hao Zhang

Doctoral Dissertations

Recent progress in magnetism has been driven by embracing the complexity associated with entangled spin, orbital, and lattice degrees of freedom and by understanding the emergent quantum behaviors of magnetic systems. Over the past decades, intense efforts have been devoted to “extreme quantum materials” comprising low-dimensional lattices of spin S = 1/2 degrees of freedom, that are candidates to host quantum spin liquid phases with no classical counterpart. Finite-spin (S ≥ 1) systems that exhibit ground states with short-ranged entanglement have not been the center of much attention because they are expected to behave semi-classically. However, as we will demonstrate …


Nanoscale Studies Of The Ferroelectric And Electromechanical Properties Of Hafnia-Based Capacitors, Pratyush Buragohain Aug 2022

Nanoscale Studies Of The Ferroelectric And Electromechanical Properties Of Hafnia-Based Capacitors, Pratyush Buragohain

Theses, Dissertations, and Student Research: Department of Physics and Astronomy

The work presented in this dissertation aims to provide nanoscopic insights into the electrical and electromechanical behavior of the recently discovered ferroelectric HfO2 or hafnia-based capacitors. Hafnia-based ferroelectrics are highly promising for technological applications due to compatibility with the existing Si technology. To realize the full potential of hafnia, however, requires comprehensive understanding of its properties. In this regard, this dissertation hopes to bridge a gap between an understanding of the nanoscopic and macroscopic properties of hafnia by performing combined high-resolution piezoresponse force microscopy (PFM) and pulse switching studies.

More specifically, the dynamics of domain nucleation and wall motion …


Topological States In Matter, Hasitha W. Suriya Arachchige Aug 2022

Topological States In Matter, Hasitha W. Suriya Arachchige

Doctoral Dissertations

Topologically nontrivial spin textures, mesoscopic spin configurations that cannot be continuously transformed to an elementary magnetic configuration such as a ferromagnet or antiferromagnet, are of interest due to their ability to exhibit magnetic solitons, with topological protection. Such properties have the potential for applications in future data storage and communication devices. For example, spin textures found in materials such as MnSi, Cu2OSe3, Co-Zn-Mn alloys, and GaV4S8, commonly known as skyrmions, are driven by the interplay of atomic-scale exchange interactions, single-ion anisotropy, and an applied magnetic field. Of particular importance to this class of materials is the presence of a Dyaloshinski …


Study Of Thermoelectric And Lattice Dynamics Properties Of 2d Layered Mx (M = Sn, Pb; X = S, Se, Te) And Zrs2 Compounds Using First-Principles Approach, Abhiyan Pandit Aug 2022

Study Of Thermoelectric And Lattice Dynamics Properties Of 2d Layered Mx (M = Sn, Pb; X = S, Se, Te) And Zrs2 Compounds Using First-Principles Approach, Abhiyan Pandit

Graduate Theses and Dissertations

The aim of this dissertation is the investigation of thermoelectric and lattice dynamics properties of two-dimensional (2D) MX (M = Sn, Pb; X = S, Se, Te) and ZrS2 compounds based on the first-principles density functional theory. The dimensionality reduction (e.g., using 2D structure) of bulk materials is found to have enhanced thermoelectric efficiency. This enhancement is attributed to the increase of the Seebeck coefficient as a result of higher electronic density of states near the Fermi level in low-dimensional materials. In addition, lowering the dimensionality increases phonon scattering near interfaces and surfaces in 2D materials, which leads to a …


Numerical Studies Of Correlated Topological Systems, Rahul Soni Aug 2022

Numerical Studies Of Correlated Topological Systems, Rahul Soni

Doctoral Dissertations

In this thesis, we study the interplay of Hubbard U correlation and topological effects in two different bipartite lattices: the dice and the Lieb lattices. Both these lattices are unique as they contain a flat energy band at E = 0, even in the absence of Coulombic interaction. When interactions are introduced both these lattices display an unexpected multitude of topological phases in our U -λ phase diagram, where λ is the spin-orbit coupling strength. We also study ribbons of the dice lattice and observed that they qualitative display all properties of their two-dimensional counterpart. This includes flat bands near …