Virtual Open House Agenda (Eastern Standard Time)
Sunday, March 7th
12:30 Women In Physics panel (presenters; faculty, postdocs, current grads) (Zoom)
1:30pm - Professor Michael Poirier, Chair (Zoom)
1:40 pm – Welcome & Virtual event logistics – Prof. Jon Pelz, Crystal Moloney, Kris Dunlap (Zoom)
1:50 pm – Introduce yourselves (Zoom)
2:10 pm – Grad Program Overview– Prof. Jon Pelz, Chair of Physics Graduate Studies & Research (Zoom)
3:10 pm - Climate and Diversity Committee - Prof. Jay Gupta (Zoom)
3:30 pm – Presentation & Discussion -Physics Graduate Student Council (PGSC) (Zoom
4:30 pm – Reminders about next events on Monday – PGSC
4:45 pm – Research Breakout rooms (Zoom)
7:00 pm – APS Chapter Presentation
Monday, March 8th
8:30am-9:30am International students info session (zoom)
9:30am – 10am Queer Folx Coffee hour (zoom)
10:00 am – 12:15 pm – Virtual Poster Session (Discord)
10:30 – 11:00 – Astronomy Coffee (Astro Coffee) (Zoom)
12:45-1:45 – Lunch with 1st and 2nd years during 6780 (Zoom)
2:00 – 5:00 – Faculty Meetings (see below for list of research areas, faculty and their meeting times and Zoom links)
3:30 pm – 4:00 pm – Polaris mentoring initiative (Discord or Zoom TBD)
4:30 pm – 5:15 pm – Society of Women in Physics (SWiP) (Discord or Zoom TBD)
OSU Virtual Campus Tour
You can use the interactive map to check out campus hot spots like the Physics Research Building, the RPAC, the Oval, and the Shoe Stadium.
About Columbus, Ohio
See what makes Columbus great, featuring downtown Columbus - click here
Please use the Discord server link to ask questions. This was provided in your RSVP email.
Virtual Poster Session
Poster session will be held in our Open House Discord channel. March 8th 10am-12:15pm EST
(poster abstracts are at the bottom of the page.)
Research Group Abstracts
The Strong Field Simulator: An Attosecond Study of Electron Recollision
An atom or molecule can be ionized by an external electric field if it is strong enough to bend the attractive potential of the nucleus so that the electron can escape via quantum tunneling. The alternating electric field of an ultrafast laser pulse, typically femtoseconds (10-15) in duration, can drive this same tunneling ionization process with an interesting twist, whereby the electric field can turn and accelerate the electron to collide with the same atom or molecule it had escaped. This type of collision between an electron and ion that were previously bound together is called recollision. The electron’s trajectory after ionization can be understood classically meaning the probability and energy of the recollision is determined by the moment the electron first escapes the atom or molecule. The three-step process of tunneling ionization, acceleration, and recollision has been studied for several decades by measuring the kinetic energies of elastically scattered electrons, the rate of double ionization from inelastic collisions, and the amount of eXtreme UltraViolet (XUV) light produced by recombination of the electron and ion. This has birthed an entirely new field of attosecond (10-18) physics, as the XUV light produced by recollision are laser like pulses of attoseconds duration. For a sense of scale, in one attosecond light will travel the length of a water molecule and in the Bohr model of atomic Hydrogen it takes 152 attoseconds for the lowest energy electron to orbit the nucleus. We report on a novel attosecond study of recollision where XUV pulses are used to ionize gas targets in the presence of a strong InfraRed (IR) field, this technique dubbed a Strong Field Simulator. One difficulty of studying recollision is that quantum tunneling can happen at any time within the IR field, some moments being more probable than others, so only a sum of results from many different trajectories are observable. Without some additional stimulus, the dynamics of individual trajectories are hidden away from typical strong field experiments. In Strong Field Simulator experiments, the ionizing XUV pulses serve to replace the tunneling step, while the IR field still accelerates the electron and drives recollision creating an analogous process to the three-step process. Separating the ionization step from the IR field, we isolate and therefore select the moment of ionization, and correspondingly the electron’s trajectory, by varying the arrival time of the pulsed XUV and IR fields. The double ionization in Helium is of particular interest, as electron recollision knocking off a second electron can be thoroughly modeled in this elementary system. Discrepancies between theory and experiment will require updating models of electron correlation. These models are fundamental to interpreting and predicting the electronic structure of chemicals and semiconductors using computational techniques such as Density Functional Theory.
Prof. Fengyuan Yang, Experimental Condensed Matter Physics
Prof. Fengyuan Yang’s research focuses on spin, magnetic, and topological phenomena in singlecrystalline films and heterostructures of complex materials, such as the magnetic garnets shown in the figures below. His group uses an innovative off-axis sputtering technique and molecular-beam epitaxy for high-quality epitaxial film growth of a variety of complex materials, which provides a platform for the exploration of new sciences and development of new technologies. Current research projects in the Yang group includes: (1) complex oxide epitaxial films for magnetoelectronic and spin transport applications, (2) terahertz spin electronics based on antiferromagnetic insulators, (3) magnetic skyrmions in magnetic insulator heterostructures, (4) ultrafast electrical switching of antiferromagnetic spins, and (5) static and dynamic interfacial magnetism. These research projects are funded by National Science Foundation (NSF), Department of Energy (DOE), the Center for Emergent Materials (an NSF MRSEC), NSF Major Research Instrumentation program, Defense Advanced Research Projects Agency (DARPA), and Multidisciplinary University Research Initiatives (MURI) by Air Force Office of Scientific Research (AFOSR).
Our research focuses on exploring the emergent phenomena that appear at interfaces, both literal and metaphorical. On the literal side, we are exploring magnetism and spin transport at the interface between magnetically ordered or spin polarized materials and nonmagnetic metals and semiconductors. This physical interface gives rise to phenomena not present in homogeneous bulk systems ranging from traditional spin injection, to magnetic-resonance driven spin pumping, to spin-thermal effects such as the spin Seebeck effect.
Taking a more metaphorical view, we are also interested in the interface between Physics and Chemistry, in particular the study of magnetism and magnetic resonance in organic-based magnetic materials. For example, we are exploring the impact of metal and ligand substitution on the DC and microwave properties of organic-based magnetic materials, revealing surprisingly high magnetic ordering temperatures (greater than 600 K) and extraordinarily narrow-linewidth (high quality factor, Q ~ 8,000) ferromagnetic resonances that rival the best inorganic materials (such as yttrium iron garnet, YIG). These high-Q resonances have potential applications in coherent magnonics ranging from microwave electronics, to magnonic crystals, to quantum information.
In addition to these established programs we have developing efforts in 2D materials, another literal interface where the material itself can be thought of as 100% interface, and DNA based nano-machines, a metaphorical interface between the precise control of DNA structure afforded by Biology and fundamental questions in nanoscience posed by Physics.
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Intense Few-Cycle Pulse, Conical Pit Interaction Simulations Predicting Extreme Material States
Joseph R. Smith1 , Simin Zhang1 , Vitaly E. Gruzdev2 , and Enam A. Chowdhury1 1Department of Materials Science and Engineering, The Ohio State University, Columbus, OH, 43210, USA, 2Department of Physics and Astronomy, University of New Mexico, Albuquerque, NM, 87106,USA email@example.com
Abstract: We use fully three-dimensional particle-in-cell simulations to model intense few-cycle pulses interacting with nano-structured conical pits in fused silica and report on laser damage creation of high energy density conditions and excited electron dynamics. © 2021 The Author(s)
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Direct Electron Acceleration by Radially Polarized Ultra-Intense Laser Focus During Ionization of High Charge States of Neon
Nour El Houda Hissi1*, Gregory K. Ngirmang2 and Enam A. Chowdhury1 1Department of Material Sciences and Engineering, The Ohio State University, Columbus, Ohio, 43210, USA 2National Academies of Sciences, Engineering, and Medicine Fellow Extreme Light Group, Air Force Research Laboratory, Dayton, Ohio, 45433, USA *firstname.lastname@example.org
Abstract: We investigate direct acceleration of electrons produced during ionization of Neon gas using a tightly focused and radially polarized Petawatt-class short pulse lasers. Gigaelectron volt (GeV) energies are reached at specific laser wavelengths and spot sizes. © 2020 The Author(s)
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Ultrashort Pulse Induced Micro-explosion Time Resolved Dynamics in Bulk UV Fused Silica
Md Mohsinur Rahman Adnan1* , Abdallah A. AlShafey2 , Justin Twardowski3 , Noah Talisa2 , Michael Tripepi2 , Enam Chowdhury3,1,2,** 1 Department of Electrical and Electronic Engineering, The Ohio State University, 2015 Neil Ave, Columbus, OH 43210 2Department of Physics, The Ohio State University, 191 W. Woodruff Ave, Columbus, OH 43210 3Department of Materials Science and Engineering, The Ohio State University 2041 N. College Rd, Columbus, OH 43210 Corresponding Author: email@example.com*, firstname.lastname@example.org**
Abstract: Ultrafast dynamics of ultrafast single pulse induced micro-explosions in bulk fused silica was captured using.time resolved shadowgraphy. Experimental and theoretical considerations identify such micro-explosions creating warm dense matter (WDM) states.
Prof. Kovchegov is a world-leading expert in high-energy QCD. QCD is an abbreviation for Quantum Chromodynamics, the theory of strong interactions. The research of Prof. Kovchegov’s group is centered around understanding the proton structure, including thephysics of gluon saturation and the proton spin puzzle.
Identifying and manipulating atomic-scale defects in electronic materials, from thin films down to 2D, nanowires, and quantum dots–Brenton Noesges, Micah Haseman, Prof. L.J. Brillson
The Brillson group is a broad science and engineering program in the structure and properties of surfaces and interfaces of electronic materials at the atomic and nanometer scale, emphasizing wide band gap semiconductors for micro-and optoelectronics, semiconductor heterostructures for renewable energy, semiconductor transistors for bioelectronics, thin film dielectrics for insulating gate structures, and complex oxides for spintronic, communications, radar and ultrasensitive antenna applications. Controlling atomic-scale defects in electronic materials becomes increasingly important as everyday devices continue shrink, and consumers expect improved performance, reduced power consumption, lower cost, and/or longer lifespans. Defects generally reduce performance, for example, by slowing down electrons within conducting layers or limiting the number of write cycles in computer memory or recharge cycles in batteries before failure. Defects can also strongly impact systems used to study quantum effects like two-dimensional materials, nanowires and quantum dots. However, defects are not entirely unwanted, and, in some applications, a controlled number of defects can be useful, such as when making a metal contact to a zinc oxide (ZnO) nanowire where some defects in the ZnO beneath the contact can control the electrical characteristics of that contact. We collaborate with researchers from around the world to investigate and develop treatments to manipulate defects using a combination of advanced growth, surface treatment, microscopy and spectroscopy techniques. The primary technique we use to identify defect is depth-resolved cathodoluminescence spectroscopy (DRCLS) which send an electron beam at a sample’s surface to generate light emission containing information about the electronic bands, or energy levels, inside the material. Defects such as missing or substituted atoms often create their own energy levels which appear in a DRCLS measurement and can uniquely fingerprint specific defects. For very small samples, we use a scanning electron microscope (SEM) which has an electron beam only tens of nanometers wide to collect DRCLS. With this instrument, we can do hyperspectral imaging (HSI) which produces two-dimensional (2D) images where each pixel contains a full cathodoluminescence spectrum in order to map spatial defect distributions. Our SEM has been upgraded with two nano-manipulator arms to move defects by applying electric fields across sample surfaces and monitoring the changes with HSI. In our lab in the Physics Research Building, we have a set of custom interconnected vacuum chambers that allows us to create, measure and modify electronic materials without ever being exposed to foreign contamination. The lab includes a molecular beam epitaxy (MBE) system, which is like atomic-scale spray painting, for producing high-quality thin films. The MBE is connected to an x-ray photo-electron spectroscopy (XPS) system which provides chemical bonding information and atomic ratios for determining chemical composition, and a DRCLS system for probing defect states. These chambers are also connected to a chamber for gentle surface treatments via remote plasma (oxygen or hydrogen) which can gently clean the sample surface and fill in missing atoms in some materials. In conclusion, the research using this array of atomic-and nanoscale research techniques enables our group to explore both the fundamental physics of semiconductors but also to discover principles that can enable the next generation of electronic devices.
Brillson Group website –http://www2.ece.ohio-state.edu/~brillson/Prof. Brillson’s College of Engineering page –https://ece.osu.edu/people/brillson.1
The Poirier lab has two primary research programs that are interconnect.
The first primary research program is focused on how the organization of the human genome regulates gene expression. Our genomes are organized into physical polymers, i.e. chromatin fibers, where each chromosomal DNA molecule is repeatedly wrapped into nanometer sized spools, i.e. nucleosomes that contain about 50 nm of DNA each. This results in our 1-meter length of genomic DNA being organized into about 20 million nucleosome spools. The physical properties of nucleosomes and chromatin fibers are key regulators of all DNA processing including gene expression. However, the physical mechanisms by which nucleosomes and chromatin function to control gene expression is not understood. This research program relies on a cross-disciplinary approach that combines biochemical, biophysical and single molecule (Fig. 1) methodologies is to understand the physical basis of chromatin regulation of gene expression. This program is largely fund by the National Institutes of Health. The second primary research direction is in the field of DNA nanotechnology. We are focused on developing and understanding DNA based nanodevices that are engineered via DNA origami. DNA origami is a rapidly emerging approach that is uniquely suited to create multi-functional devices out of DNA for biological and nanoscience applications. These DNA based devices have unparalleled control over nanoscale geometry, are highly biocompatible, can be controllably reconfigured, and can be functionalize with many components in a site-specific manner. We are currently working on three separately funded projects. (1) Develop DNA based nano-calipers to detect mesoscopic structural changes within chromatin both in vitro and in vivo (2) Develop devices that integrate DNA origami nanodevices with either gold or magnetic nanoparticles to create reconfigurable devices that can externally controlled optically and or magnetically. (3) Develop new DNA origami nanomaterials with new sensing, communicating and pattern forming properties (Fig. 2) These projects are funded by the Department of Energy and the National Science Foundation including an NSF EFRI (Emerging Frontiers in Science and Innovation) grant and an NSF DMREF (Designing Materials to Revolutionize and Engineer our Future) grant.
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Elan Shatoff abstract
RNA binding proteins are fundamental to many cellular processes. Double stranded RNA binding proteins (dsRBPs) in particular are crucial for RNA interference, mRNA elongation, A-to-I editing, host defense, splicing, and a multitude of other important mechanisms. Since dsRBPs require double stranded RNA to bind, their binding affinity depends on the possible secondary structures of the target RNA molecule. Here, we introduce a quantitative model that allows calculation of the effective affinity of dsRBPs to any RNA given a base affinity and the sequence of the RNA, while fully taking into account the entire secondary structure ensemble of the RNA. We implement this within the Vienna RNA folding package while maintaining its O(n 3 ) time complexity. We find that proteins will bind to random sequences with a ~100-fold change in effective binding affinity, simply based on the structural interactions between their double stranded footprint and the rest of the molecule. We also validate our quantitative model by comparing with experimentally determined binding affinities for transactivation response element RNA-binding protein (TRBP).
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Kyle Crocker research abstract
A quantitative model for a nanoscale switch accurately predicts thermal actuation behavior
Kyle Crocker, a Joshua Johnson, bc Wolfgang Pfeiferad, Carlos Castrod , and Ralf Bundschuh∗abe f g
Manipulation of temperature can be used to actuate DNA origami nano-hinges containing gold nanoparticles. We develop a physical model of this system that uses partition function analysis of the interaction between the nano-hinge and nanoparticle to predict the probability that the nano-hinge is open at a given temperature. The model agrees well with experimental data and predicts experimental conditions that allow the actuation temperature of the nano-hinge to be tuned over a range of temperatures from 30◦C to 45◦C. Additionally, the model reveals surprising physical constraints on the system. This combination of physical insight and predictive potential is likely to inform future designs that integrate nanoparticles into dynamic DNA origami structures. Furthermore, our modeling approach could be expanded to consider the incorporation, stability, and actuation of other types of functional elements or actuation mechanisms integrated into nucleic acid devices.
Connolly and Beatty - Astroparticle Experiments at OSU
The Connolly and Beatty groups look for high-energy neutrinos of galactic, astrophysical, or cosmogenic origins by observing their signatures in the ice of Antarctica. There are numerous experiments focusing on different signatures, like the optical Cherenkov effect (IceCube), Askaryan Radiation (ANITA, ARA), isotopes in the cosmic ray flux (HELIX), and radar reflections off particle cascades in the ice (RET). We are involved in the development of hardware, analysis, and simulations; with additional explorations in applying genetic program (GENETIS) to future development of hardware. We are also heavily involved with outreach through the ASPIRE Workshop, which allows high school women to get hands-on experience with equipment and software used by physicists.
Dick Furnstahl Group: Low-Energy Nuclear Theory (LENT)
PDF with links:
Prof. Dick Furnstahl’s group does theoretical research on low-energy nuclear physics. In this context, “low-energy” means the structure and reactions of bound atomic nuclei (as opposed to relativistic heavy-ion collision physics also studied at OSU) with applications to astrophysics, such as nucleosynthesis and neutron star physics. The research by group members develops and applies:
- renormalization group (RG) methods to nuclei;
- effective field theories (EFT) for few- and many-body systems;
- Bayesian statistics and machine learning for nuclear UQ and physics discovery;
- computational physics methods. There are typically 2-3 graduate students doing thesis work (i.e., past candidacy) at any given time.
Papers from the last two years co-authored by Prof. Furnstahl can be found here; these include work in the last year by graduate students Anthony Tropiano (Operator evolution from the similarity renormalization group and the Magnus expansion), Jordan Melendez (How Well Do We Know the Neutron-Matter Equation of State at the Densities Inside Neutron Stars? A Bayesian Approach with Correlated Uncertainties and several more by Jordan), and Alberto Garcia and Patrick Millican (Efficient emulators for scattering using eigenvector continuation).
Recent talks by Prof. Furnstahl (the slides are linked) include "Short-range-correlation physics in atomic nuclei," "Turning the nuclear EDF method into a proper EFT," "Similarity Renormalization Group (SRG) in Nuclear Physics," and "Theory error bars for nuclei." Follow the links for slide from talks at the Fall, 2020 APS Division of Nuclear Physics (virtual) meeting by LENT graduate students Alberto Garcia, Patrick Millican, Anthony Tropiano, and Mostopha Hisham.
The LENT group has several funding sources: the National Science Foundation (abstract from current grant), the Department of Energy through the SciDAC NUCLEI project, and the BAND Framework Project (see also the BAND Manifesto). If you have any questions, please do not hesitate to send email to Furnstahl.email@example.com.
Student Will Koll abstract for Jay Gupta research group
Scanning Tunneling Microscopy Toolkit for 2-D Materials
Rapid improvement in our ability to characterize materials with subatomic resolution has enabled us to investigate questions in condensed matter physics that were previously beyond our experimental capabilities. Scanning tunneling microscopy (STM) leverages the inherently wavelike nature of electrons to probe surfaces at sub-angstrom length scales. While traditional STM gathers topographical information about the sample, closely related techniques involving an STM tip facilitate direct access to local electronic and magnetic states. Herein we explore the toolbox of STM to study 2D magnetic textures, semiconductor defects, and more.
Skinner group: condensed matter theory
Prof. Brian Skinner's group works on problems at the intersection of quantum solid state physics and classical statistical mechanics.
A good portion of the group's work is concerned with explaining and predicting the electronic properties of materials. Particularly interesting are the so-called "topological materials," which fall outside of the traditional dichotomy of all materials as either metals or insulators. Figuring out what these topological materials can do that traditional materials cannot do is one of the central focuses of our work. Much of this work is done in close collaboration with experimental groups.
Another side of our work is exploring problems in quantum and classical statistical mechanics. These problems range in topic across a variety of different fields, and often take inspiration from ideas in traditional solid state physics. Recent projects include studying the dynamics of quantum entanglement and the evolution of "fracton" systems, for which both charge and dipole moment are conserved over time.
In terms of technical methods, we generally try to use the simplest theoretical description that we can get away with, and we are always learning new things. We also use some small-scale numerical simulations.
For more information about our group, and to see examples of recent projects, you can visit the group's web page.
Bockrath group’s research interests focus on the electronic properties of two‐dimensional (2D) van der Waals materials. Individual atomic planes of the bulk crystal can be exfoliated, with the extracted monolayers often having surprising new properties compared to the bulk material. Our current efforts are focused on three main areas: Topological Electronic States. Many 2D materials exhibit electronic states with topological properties. These properties can be intrinsic or emerge in conjunction with superconductivity. These states show promise towards topological quantum computing and solid‐state manipulation of quantum information. Proximity Coupling. An advantage of 2D materials is that the individual layers can be readily stacked to make atomically precise heterostructures. Such heterostructures can be tailored to create synthetic materials that do not appear in nature and exhibit novel phenomena such as enhanced spin‐orbit coupling or magnetic properties that can potentially be exploited for novel devices. Twistronics. The properties of heterostructures can also be tailored by the interlayer twist angle, giving even more degrees of freedom with which to tune material properties. For example, the spatial interference between the twisted lattices creates a long‐wavelength superlattice. This superlattice can profoundly alter the behavior of the materials, producing a plethora of interacting many‐body states and correlated phases that exhibit such behavior as tunable superconductivity or magnetic states. This provides an excellent testing ground for theories of interacting quantum states of electrons in materials.
Prof. Chun Ning (Jeanie) Lau, Experimental Condensed Matter
Quantum Materials Research
The size and dimension of a material has profound effects on its electronic, optical, thermal and mechanical properties. When one or more of the dimensions of a material is reduced to atomic scale, quantum mechanical efforts becomes important. The many-body interactions become more prominent and often dominate over the, giving rise to many correlated phases such as ferromagnetism, antiferromagnetism, superconductivity, charge density waves, Wigner crystals, etc. Stacking atomically thin layers together provides another route of controlling, manipulating and tailoring the properties of materials via proximity effect and twistronics, leading to designer quantum materials. Currently we are studying spin, charge, heat and supercurrent transport in
- monolayer and few-layer graphene
- 2D semiconductors such as InSe, phosphorene, and MoS2
- quasi-1D topological insulators such as Bi4I4
- 2D magnets such as CrI3
- heterostructures of van der Waals materials by stacking, proximitization and twisting
Hammel Group Research
The Hammel group uses magnetic resonance to study electron spin and magnetization dynamics to understand magnetic properties and interactions in a variety of magnetic systems, from exotic magnetic materials to complex heterostructures for spintronic applications. Our current active research topics include 1) nanoscale imaging of heterogeneous magnetic structures such as interfaces, domain walls, and skyrmions, 2) spectroscopic studies, and electrical and magnetic control of spin dynamics and damping in ferromagnetic and antiferromagnetic systems, and 3) understanding of the microscopic spin interaction mechanisms in the novel spin systems. We develop and apply various high-sensitivity magnetic resonance techniques that exploit force, optical, and electrical sensing. Ferromagnetic resonance force microscopy is a nanoscale imaging tool for local detection of the internal field, detected using a scanned cantilever with a micromagnetic tip. Using this technique, we can image the static and dynamic magnetic properties of magnetic materials in a spectroscopic manner with nanoscale spatial resolution. Currently we are using this technique to intensively study two-dimensional materials, and it can also be used to study magnetic nanostructures and potentially exotic magnetic textures such as skyrmions. Optically detected magnetic resonance using nitrogen-vacancy (NV) centers in diamonds is another powerful technique for three-dimensional nanoscale imaging of stray magnetic fields from target samples such as biological organisms and electronic devices with exceptionally high sensitivity and resolution. We are using this to study spin waves in microscopic samples and developing relaxometric techniques for detecting magnetic resonance in highly anisotropic magnets and in antiferromagnets at frequencies well above the NV electron spin resonance frequency of 2.8 GHz with the goal of pushing into the THz regime.
CMS research faculty - Chris Hill, Brian Weiner,
Polaris is a student-led partnership between undergraduate and graduate physics and astronomy students at The Ohio State University dedicated to fostering a more diverse, equitable, inclusive, and accessible undergraduate experience in the OSU Departments of Physics and Astronomy. Polaris aims to increase retention of underrepresented and non-traditional groups in the physics and astronomy BS programs by providing professional and academic mentorship for these groups. We seek to aid undergraduate students in creating and maintaining an inclusive and supportive learning community. To this end, Polaris relies on graduate mentors in the Departments of Physics and Astronomy to meet weekly with undergraduate mentees as part of our mentorship course.
Milli-charged Particle Detector for LHC P5
Christopher Hill, Brian Francis
Randeria Group Abstract:
Professor Mohit Randeria’s group works on quantum condensed matter theory. Specific areas of interest include:
- Topological spin textures in chiral magnets
- Magnetism and spin orbit coupling in complex oxides and at interfaces
- Topological quantum materials
- Superconductivity and strong correlations
- Superconductor-Insulator Transitions
- Ultracold atomic gases: BCS-BEC crossover and strongly interacting fermions
More information can be found at our group webpage: https://u.osu.edu/randeriagroup/
Presenter: Dylan Roderick
Professor Ratnasingham Sooryakumar, Experimental Condensed Matter
Micro- and nanoscale magnetic systems are the primary focus of the work in Dr. Sooryakumar’s group. Currently, there are two main magnetic systems being researched. The first involves the use of Magnetotactic Bacteria (MTB). These bacteria have magnetic organelles that allow the researchers to manipulate and effect the bacteria using external magnetic fields. The group has researched both the properties of the MTB themselves, and used the MTB as a tool to probe other systems. This project has had significant collaboration with biology research groups.
The other portion of the lab is focused on the design and use of nanoscale devices controlled via external magnetic fields. These devices are made using DNA origami – DNA that is folded into stable shapes for a variety of uses. By combining DNA origami with microscopic magnetic plastic beads, we get controllable tools only visible under a microscope. Researchers are then able to probe single molecule reactions, pico-scale forces, and other microscopic phenomena using the DNA origami tools. The work with DNA origami collaborates with bioengineering research labs.
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Dr. Furnstahl nuclear theory group
Eigenvector Continuation for Two-Body Scattering
Eigenvector continuation (EC) is a technique that relies on solutions to a Hamiltonian for several sets of known parameters to formulate a basis, which can be used to accurately interpolate and extrapolate solutions for the same Hamiltonian with different parameters. Until now, this has only been implemented for the bound state problem. Using the Kohn variational method, we show that EC can be adapted to the two-body scattering problem in coordinate space in the form of a simple matrix inversion. In addition, we discuss how to deal with ill-conditioned matrices that naturally arise. Furthermore, we generalize to include the Coulomb and non-local potentials, as well as extending the method to momentum space.
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Furnstahl nuclear theory group
The Similarity Renormalization Group in low-energy nuclear theory
In analyzing scattering observables, there is scale and scheme dependence in the factorization of structure and reaction components. The similarity renormalization group (SRG) is well-suited to analyze these components by applying SRG transformations to wave functions and the corresponding operators to evolve to low resolution, tuning the scale with the SRG decoupling parameter. We evolve a high-resolution nucleon-nucleon interaction to low resolution, decoupling the low- and high-energy physics. We show that short-range correlation (SRC) physics is shifted from the wave functions to consistently evolved operators. We demonstrate that a high-resolution description of SRC physics such as the ratio of proton-neutron over proton-proton pairs in nuclei at various relative momenta can be equivalently described with simple calculations at low resolution.
Reminder that you can chat your questions to OSU Students and to Crystal and Kris via the Discord channel that was provided in the Open House information email.
Zoom meetings will be Monday March 8th ** 2pm to 5pm (Eastern Standard Time) unless otherwise noted. **please note that meeting times vary per faculty member according to their individual schedules.
The meeting times and zoom links will be emailed to you, and posted in Discord.
When you login to discord with the link provided in your open house details email, you should land on this welcome page. If you are a prospective student, please select "P". Once you've done so the left side of the screen will show the different chat channels you can ask questions to current grad students in.
For the poster session scroll down to the voice channels and Monday 2-5pm you can view poster presentations, and ask the professors and grad students questions.