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MATERIALS SCIENCE APPLIED TO DENTISTRY - AN OVERVIEW
Fred Rueggeberg, DDS, MS
Professor and Section Director, Dental Materials
Department of Restorative Sciences
Dental College of Georgia at Augusta University
February 22, 2019
2:30 - 3:30
Science Hall W1002
For 150 years, researchers (as well as clinician-scientists) have searched for an
“ideal restorative material.” Included materials include metals, polymers, and ceramics
available as an astonishing array of products. Not only are definitive restorative
products a primary focus of interest, but, in addition the many types of materials
used in order to generate the final restorative products involve a tremendous amount
of materials science consideration: impression materials, dental stones, casting investments,
waxes, photocuring devices, color measurement instruments, color-corrected lighting
conditions, soldering (brazing), to name a few. And now, with the introduction of
digital technology, we are dealing with 3D additive and subtractive processes: digital
printing and milling. The contemporary clinician must keep up to date with all these
technologies, and be able to know if and when it is advantageous to introduce costly
and innovative products into his/her practice in order to keep up with the times,
but also to provide predictable, long lasting restorations that the patients like
(and will talk about!). Thus, this presentation will provide a short overview of the
tremendous challenges facing dentists in restoring teeth, as well as the future opportunities
to introduce cutting edge products into practice.
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ATOM-BY-ATOM ENGINEERING OF OXIDE THIN FILMS AND NANOCOMPOSITES VIA MOLECULAR BEAM
EPITAXY
Ryan Comes, PhD
Assistant Professor of Physics
Department of Physics
Auburn University, Auburn, Alabama
March 15, 2019
1:00 - 2:00 p.m.
Science Hall W1002
Complex oxides comprised of multiple positively charged metal cations exhibit a host
of intriguing and useful properties for new technologies. Perovskite oxides with the
chemical formula ABO3 and spinel oxides with the formula AB2O4 have some of the richest behavior. These materials may be metallic, semiconducting,
or insulating, and exhibit ferroelectricity, with a built-in electric polarization,
ferromagnetism, or superconductivity. This combination of properties in a single class
of materials offers rich opportunities for engineering of unusual combinations of
behavior through the design of multi-layer thin film materials. Through the use of
molecular beam epitaxy (MBE), we are able to engineer these materials down to the
atomic level so that interfaces between two different perovskites can be controlled
to produce desirable properties. In this talk I will present two examples of this
type of interfacial engineering, showing how we can design, model, and characterize
these properties through a wide variety of techniques. I will discuss our work engineering
interfacial termination in polar/non-polar heterojunctions and superlattices comprised
of SrTiO3 and polar transition metal perovskites (LaFeO3 and LaCrO3) to engineer electric fields in these materials. In spinel-perovskite nanocomposites,
we show for the first time that MBE can be used to grow these vertically-aligned nanocomposites
that are of interest for magnetic and catalytic applications. These results open up
a wide range of new opportunities to design multilayer and nanostructured materials
to achieve specific properties that cannot be found in the bulk.
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THE LAST ROADBLOCK TO MAJORANA ZERO MODES AND TOPOLOGICAL QUANTUM COMPUTATION IN SEMICONDUCTOR
HETEROSTRUCTURES
Sumanta Tewari, PHD
Associate Professor of Physics
Department of Physics and Astronomy
Clemson University, Clemson, South Carolina
March 22, 2019
1:00 - 2:00 p.m.
Science Hall W1002
Abstract: With the discovery of topological insulators (TI), studies of topological
phases have tremendously accelerated in the last few years. Examples include 3D TI,
2D quantum spin-Hall insulator, topological Dirac and Weyl semimetal, and topological
superconductors (TS). In recent years we proposed a semiconductor-superconductor (SM-SC)
heterostructure as an excellent candidate for realizing a topological superconductor.
Recent experiments on this system have claimed that the long-sought-after Majorana
fermions, first proposed in high energy physics in 1929, may have been realized at
the interface between this TS system and metallic leads, paving the way for topological
quantum computation (TQC). In this talk I will discuss the theory of Majorana fermions
and TQC, overview of the current experiments, and our recent work on Andreev bound
states in SM-SC heterostructures, illustrating why the claims of experimental success
may be hugely encouraging but somewhat premature.
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