ABSTRACTS for CLASS of 2022 PHYSICS SENIOR PROJECTS  as of September 27, 2021

These abstracts describe work that students PLAN to do in their projects; the abstracts for their final papers will generally be very different.

Robertson Albrecht with Prof. Giuseppe Strangi

Random Lasing in Turbulent Dye-Doped Liquid Crystals

Evidence for random lasing in dynamically-scattered-dye-doped liquid crystals will be investigated. The anisotropic behavior of the partially ordered liquid crystal provides coherent backscattering and weak localization of light, that in presence of gain media (dye molecules or quantum dots) can generate random laser light. As a voltage is applied across a liquid crystal cell, the liquid crystal will undergo different regimes of turbulent/chaotic behavior. Several fluorescent and lasing behaviors are expected as the voltage is varied across the cell. Sharp random lasing peaks are expected after the collapse and narrowing of an underlying fluorescence curve, above a certain threshold pump energy. A comparison of laser action features and properties for this system will be investigated.

Erol Balkovic with Dr. Francesco Volpe  (Renaissance Fusion Company)

Accurate Generation of Stellarator Fields using Finite-Divergence Surface Currents

Stellarators confine thermonuclear plasmas using three-dimensional, topologically-toroidal magnetic fields. Designing electromagnetic coils that produce the desired fields is a non-trivial problem with direct implications for the engineering and physics performance of the final device. Typically, coils are obtained from surface-currents of the coil winding surface (CWS)—a toroidal surface enveloping the plasma—which are calculated from the condition of having zero surface divergence. We generalize this approach here through development of a new code, SOURCECOIL, which employs the full Hodge representation of the surface-current, including the term that allows for sources and sinks on the CWS. In practice, this is equivalent to introducing current-feeds on the CWS and deploying non-closed current-filaments alongside standard, closed coils. The new approach allows for novel current configurations, greater flexibility in coil design, and higher accuracy in matching the target fields. Further, we implement a gradient-based local optimization scheme that finds the optimal number and placement of current sources and sinks, along with optimal current magnitudes. We compare our approach to traditional divergence-free current solving schemes such as REGCOIL and point out the benefits for use in design of future stellarator reactors.

Duncan Clayton with Prof. Benjamin Monreal

 Using Salt Caverns to House Cylindrical Particle Detectors

Widely used gas ionization detectors rely on a particle traveling through a container filled with gas. When a particle passes through the chamber, it ionizes the gas and releases a line of electrons in its path. As a result of the voltage potential between the top and bottom of the chamber, the electrons move to the anode while the ions drift to the cathode which creates a signal that can be amplified and seen. Current neutrino detectors must be built underground in artificial caverns to minimize interference from cosmic rays and other background radiation. However, these detectors must be very large in order to consistently capture events and provide room for personal. This leads to a very high cost to build new detectors. This project looks to develop a more cost-effective version of such detectors by developing a small cylindrical detector capable of being lowered into an empty salt cavern. The detector’s metallic balloon would then be inflated with a common gas used in ionization detectors, creating a deep underground particle detector with minimal mining, drastically reducing costs

Huay Din with Prof. Julia Dobrosotskaya (CWRU-MAMS)
Machine Learning for Magnetic Resonance Fingerprinting

Nowadays, Magnetic Resonance Imaging (MRI) plays a vital role in disease detection, diagnosis, and treatment monitoring. The technique works by surrounding the patient with large magnets to gauge the body’s reaction to strong magnetic fields. One issue with the technology is compromising between time of acquisition with the quality of the reconstruction. Magnetic Resonance Fingerprinting (MRF) is a technique for faster result recovery from strategic approximations of the collected measurements. While the technique is state of the art, there can be improvements in the overall precision and efficiency of determination. Network based learning methods have been successful in recent years in tackling inverse problems in imaging. We’d like to propose to not only incorporate machine learning in our solution, but also to train the network based on the physics of MR acquisition and existing theorems about noisy signal demixing in the Fourier domain. Inevitably this work will give insight into the recovery of signals from partial data, and we hope to improve efficiency and accuracy of MRF to use on patient data.

Michael Gabe with Prof. Charles Rosenblatt

Rayleigh-Taylor Instability at Liquid-Air Interface

This lab has examined Rayleigh-Taylor instability in a two-layer configuration using magnetic levitation of an aqueous mixture of manganese chloride tetrahydrate and distilled water over the oil hexadecane, but quantitative problems arose in terms of the interface’s growth rate when undergoing a Rayleigh-Taylor (RT) instability. The RT instability occurs when a dense fluid accelerates into a less dense fluid, which occurs when the magnetic field is switched off and the aqueous mixture falls to the bottom of the cell. To further our understanding of Rayleigh-Taylor instability, this experiment has two aims. The first aim is to understand whether the errors in growth rate measurement are due to impurities in water. We will examine this by replacing the distilled water in the manganese chloride tetrahydrate mixture with methanol. The second aim is to levitate methanol over air and investigate Rayleigh-Taylor instability in this configuration.

Min Gao with Prof. Xuan Gao

Heterostructures of 2D Materials: Fabrication and Characterization

2D materials are known to present disparate properties compared to their 3D counterparts. Then, heterostructure of two different monolayers brings even more possibilities in the final product. In this research, we are going to focus on exploring how interactions between two layers of 2D materials invoke new properties, which include for instance charge redistribution by tunneling and drag effects between two layers, and induced superconductivity. Our main material systems are heterostructures of two 2D semiconductors or combinations of a 2D semiconductor with a 2D superconductor. For now, available semiconductor materials are gallium sulfide and indium selenide. We assume that it is possible to achieve devices with clean atomic flat heterointerfaces via van der Waals bonding. And in this process, we are going to tune our devices’ electrical properties at low temperatures with an external electric field and magnetic field. Hopefully, at the end of this project, we can find a stable method to enhance the performance of our first semiconductor layer (e.g., higher electron mobility) or change its electronic state (e.g., inducing superconductivity) by introducing a second layer in the heterostructure form.        

Brian Gould with Prof. Shulei Zhang

Interplay Between Topological Spin Texture and Spin Current

 Spin textures possessing nontrivial real-space topology have attracted much attention in the past decade. One of the celebrated examples is magnetic skyrmion, which can be hosted in a variety of magnetic systems including chiral magnets, frustrated magnets, and magnetic multilayers with structural inversion asymmetry. The topological nature of magnetic skyrmions makes them substantially robust against disorders during their steerable motion — in contrast to conventional magnetic structures like transverse and vortex domain walls — and makes it possible to stabilize them at the nanoscale. For these reasons, magnetic skyrmions are deemed to be promising building blocks of future electronic devices including quantum computers.          

This project aims to find a scheme to efficiently control and accurately detect skyrmion motion in magnetic nanostructures, which remains to be one of the main issues in the application of magnetic skyrmions. To that end, we will theoretically investigate the interplay between magnetic skyrmions and spin current in both metallic and insulating magnetic systems, wherein skyrmions interact with two different types of spin-angular-momentum carriers, namely, conduction electrons in metallic systems and spin waves in insulating systems. In particular, we will explore the role of strong spin-orbit coupling in the dynamics of electrons and spin waves when they are intertwined with the topological spin textures and acquire extra real-space Berry phases.

Jarrell Imamura with Dr. Omar Y. Mian (Cleveland Clinic Foundation)

Identification of Drivers of Neuroendocrine Transdifferentiation of Bladder Cancer

Late stages of bladder cancer are often accompanied by appearance of a very aggressive variant of the disease, characterized by a high metastatic potential and resistance to conventional therapies. This rare (about 5%) variant demonstrates a different molecular signature, resembling that of neuroendocrine cells, and is believed to result from a so called neuroendocrine transdifferentiation (NET) of cancer cells. Better understanding of mechanisms of NET is required to develop efficient therapies. Data suggest that reversible epigenetic mechanisms might be involved in NET. We propose to search for genetic and/or epigenetic drivers of NET by utilizing an unbiased screening approache. We will develop a reporter system of NET: we will create reporter constructs for the expression of fluorescent proteins under promoters of NET marker genes and introduce them in non-NE and NE bladder cancer cell lines. These cell lines then will be used to positive and negative screening by using the insertional mutagenesis methodology.

Noah Lindsell with Prof. Cyrus Taylor

Quantum Currencies

Current cryptographic currencies solve the double-spending problem often by integrating a blockchain which is backed by hard-to-solve hash functions. This ensures that each “coin” is unique, and also maintains the value of the underlying asset via the difficulty of “mining” such coins via the solving of hash functions. Quantum mechanics presents many phenomena such as quantum teleportation, quantum digital signatures, and the no-cloning theorem which make its application to such problems extremely attractive. With respect to the no-cloning theorem, for example, the double spending problem could be theoretically solved by realizing coins in unknown quantum states, which are fundamentally unique.

Our idea is this. What if we could realize a decentralized currency, whose underlying security is based on the fact that the unit of currency behaves quantum mechanically?

Kate Okun with Prof. J. Ruhl

Modeling and Manufacturing Baffle Panels to Reduce Sidelobes in CMB Telescopes

CMB-S4 is a new project using a set of ground based instruments aimed to study the cosmic microwave background (CMB) with 21 cryogenically-cooled telescopes located at the South Pole and in the Chilean Atacama Desert.  Three of these telescopes have multiple mirrors, 5-6m in diameter, enclosed within large cabins.  If the cabins have specularly reflecting internal walls, scattered light in the instrument exits at specific angles causing significant sharp sidelobes.  We aim to reduce the contrast in these sidelobes by lining the cabin in panels that are designed to scatter light over a large range of angles rather than reflect specularly.  My research will focus on finalizing our experimental measurements of a prospective panel surface, building and improving a model of the scattering using phase sensitive ray tracing, and working to prototype the manufacture of such scattering surfaces at larger scale.  The scattering panels are made of random “noise” bumps on the surface.  I will work to design a surface with matched boundary conditions to avoid discontinuities at the seams, then use SolidWorks to create a 3D printed cylinder wrapped in the surface, and lastly imprint the design onto sheet metal using the rollers.

Phillip Popp with Prof. Walter Lambrecht

First-Principles Band Structure Calculations of LiAlO2

Ultrawide-bandgap (UWBG) semiconductors have many potential interesting applications, such as in high-power electronics and deep-UV optoelectronic devices. LiAlO2 is a candidate material for UWBG semiconductors. This project will consist of computational implementation of first-principles methods to calculate various important properties of LiAlO2 that must be understood prior to actual technological applications, including band gap/band structure, bulk moduli of various crystal structures, and transition pressures between different structures. We have carried out preliminary calculations of these properties using density functional theory (DFT), but we seek to make more accurate predictions using methods such as quasiparticle self-consistent GW (QSGW). Other phenomena that might be explored are vibrational modes and point defects. We will seek to understand the differences between these properties of LiAlO2 and the corresponding ones calculated for LiGaO2, another UWBG semiconductor candidate that has been recently studied in the Lambrecht group.

Christian Querrey with Prof. Cyrus Taylor

Quantum Currencies

 Current cryptographic currencies solve the double-spending problem often by integrating a blockchain which is backed by hard-to-solve hash functions. This ensures that each “coin” is unique, and also maintains the value of the underlying asset via the difficulty of “mining” such coins via the solving of hash functions. Quantum mechanics presents many phenomena such as quantum teleportation, quantum digital signatures, and the no-cloning theorem which make its application to such problems extremely attractive. With respect to the no-cloning theorem, for example, the double spending problem could be theoretically solved by realizing coins in unknown quantum states, which are fundamentally unique. Our idea is this. What if we could realize a decentralized currency, whose underlying security is based on the fact that the unit of currency behaves quantum mechanically?

Tong Shi with Prof. Kathleen Kash

Analysis of Electron Recombination in GaN-InGaN-ZnGeN2 Quantum Wells Using Photoluminescence Spectroscopy

 The use of GaN-InGaN commercial light-emitting diodes has revolutionized the lighting industry. Currently these devices uses roughly one-tenth of the power of incandescent light bulbs, and last 20 times as long. In principle this materials system can cover the entire visible wavelength range, but unfortunately due to increasing densities of nonradiative defects, this system has decreasing radiative efficiency at the green to longer wavelengths. Insertion of a thin ZnGeN2 film into the InGaN quantum wells has been predicted to increase the radiative efficiency. By analyzing photoluminescence spectra over a range of temperatures, information on intrinsic radiative recombination, radiative defect recombination and non-radiative defect recombination can be obtained over a range of temperature. Since inserting ZnGeN2 film into GaN-InGaN is a complicated process, defects introduced by this material might degrade the radiative recombination efficiency. In this work, photoluminescence spectroscopy will be used to evaluate the quality of the GaN-InGaN material with a thin ZnGeN2 film inserted under different growth conditions. The results will be of use in the effort to further improve the efficiency of light emitting diodes at the longer wavelengths.

Ian Stevenson with Prof. Charles Rosenblatt

Chirality of Magnetic Nanoparticles and how it Affects the Freedericks Transition

I will examine the effects of chirality and magnetic nanoparticles on the liquid crystal magnetic field Freedericks threshold.  In a thin nematic cell in qhich the director is aligned uniformly by the two substrates, an electric or magnetic filed can ve applied normal to the director.  This creates a competition between the elastic deformation energy and magneti (or electric) energy, resulting in a threshold field at which the director undergoes a distortion

I will first use a chiral silane monomer to determine if and by how much the Freedericks threshold is reduced due to the chirality induced on the liquid crystal by the silane.  Any such shift would be caused by a director twist promoted by the chiral dopant -this requires the initial director to be tilted out of plane- such that it becomes more energetically favorable to have the Freedericks transition at a lower magnetic field.  I then hope to use chiral silane ligands now decorating silica nanoparticles to observe the effect of chiral nanoparticle inclusions on the Freedericks transition.  Presumably, the combination of chiral ligands and nanoparticles will cause a further reduction in the threshold field.  Given sufficient time, I will use chiral silane ligands on magnetite nanoparticles to examine a combination of chirality and magnetic particles affecting the Freedericks transition.  Finally, I will use the achiral ligands and magnetite, which will show the effects of magnetic nanoparticles in the absence of chirality. 

Ryan Trice with Prof. Matthew Willard (Materials Science & Engineering)

Correlation of Magnetic Properties and Structure in Field Assisted Sintered Compacts

Soft magnet alloys possess large magnetization allowing for a reduction in the size and weight of magnetic components. One of the most efficient ways to further reduce the size and weight of soft magnetic components is to increase the switching field frequency. Recently, soft magnetic alloy powders have been coated with insulators to create various composite powders. These powders are then compacted using field assisted sintering furnaces to create bulk forms with alloy regions surrounded by an insulating matrix. This microstructure then enables the materials to operate at higher switching frequencies, allowing for a reduction in the size and weight of the components.

During this project, sections will be sampled across the diameter of the compacted powders and measured for density variations and magnetic performance in order to study this relationship. The magnetic properties will be measured using a vibrating sample magnetometer to produce hysteresis loops. The structure will be assessed by optical microscopy and density measurements (which will be correlated with previously collected XRD/SEM results).

References:

  1. Dong, H. Wang, G. Santillan, A. Sherman, and M. A. Willard, “Field Assisted Sintering of FeCo/MnZn Ferrite Core-Shell Structured Particles” J. of Metals (2021) in press.

 Noah Vardy with Prof. Giuseppe Strangi

Algorithmic Analysis of Random Lasing Spectra

An algorithmic analysis of emission spectra describes the effect on random laser action from Au nanoparticles dispersed in a dye doped liquid crystal. At low pump energy, the additional scattering provided by the Au nanoparticles allows for a lower random lasing threshold, as well as reduced mode competition in the Au doped samples. At mid pump energy, strong mode competition is likely for all samples, and coherent laser modes are rarely visible. With increasing pump energy above a threshold (~250 J), mode competition phenomena lead to resonant random lasing of increased intensity. In the Au-doped samples, strong random laser peaks are more likely to appear, and with lower mode competition, leading to the conclusion that Au nanoparticles facilitate random laser action at multiple pump energies. This algorithmic analysis aims to quantify physical aspects of the random laser action so as to establish a basis for statistical comparison.

Yiyang (Flynn) Zhi withProf. Giuseppe Strangi

Investigating Quantum Correlations in Light Propagating Through Nanoscaled Disordered Media

Understanding the quantum correlations between light modes scattered from disordered media is intimately tied to developments in quantum information and imaging [1, 2]. A system traditionally utilized to study random lasing – gain media dissolved in scattering systems – is ideally suited to probe such non-classical correlations. Here, we propose investigating how light scattered in media with different degrees of disorder may induce quantum correlations in the form of quantum discord or entangled states. The experiment will have several control knobs to modify the disorder and the associated scattering strength. These will include the kind of subwavelength scatterers and their concentrations (nanoparticles, liquid crystals, and metasurfaces), the various dynamic regimes (from quasi-static to turbulent) of these scatterers, and the type of the active media (laser dye and quantum dots). In this study, the output light is either directly scattered or generated by photoluminescence and random lasing processes [3]. The experimental techniques expected to be employed are power measurement, optical spectroscopy, far-field imaging, and homodyne detection. This study will investigate the existence of quantum correlations in reconfigurable disordered media – such as quantum discord – which might be significant in quantum information transfer processes.

References:

  1. Starshynov, Ilya, Jacopo Bertolotti, and Janet Anders. “Quantum correlation of light scattered by disordered media.” Optics express5 (2016): 4662-4671.
  2. Laurat, Julien, et al. “Entanglement of two-mode Gaussian states: characterization and experimental production and manipulation.” Journal of Optics B: Quantum and Semiclassical Optics12 (2005): S577.
  3. Perumbilavil, Sreekanth, et al. “Beaming random lasers with soliton control.” Nature communications1 (2018): 1-7.