Biography
https://robinson.gsu.edu/profile/baozhong-yang/

Abstact

We study numerically the interaction of ultrashort pulses with low dimensional systems, such as graphene, germanene, transition-metal dichalcogenides, Weyls’ semimetals, and flakes of such materials, i.e., quantum dots. Electron dynamics in such ultrastrong pulses is highly nonlinear, which results in such effects as generation of high harmonics, nonlinear charge transfer through the system, and residual excitations of the electron systems. The graphene-like materials also have nontrivial topological properties, which can be probed by ultrashort optical pulses with high intensity. In such strong pulses, the electrons are transferred in the reciprocal space over a relatively large distance and correspondingly the electrons can accumulate, during the pulse, relatively large topological phase, . Such an accumulation of the topological phase results in unique phenomena, which can be observed in topologically nontrivial materials, and which are governed by an effect of topological resonance that is a cancellation of the topological phase by the dynamic phase. The topological resonance results, for example, in the fundamentally fastest induction of a significant population and valley polarization in a monolayer of a transition metal dichalcogenide (i.e., MoS2 and WS2). This effect may be extended to other two-dimensional materials with the same symmetry. Thus, generated valley polarization can be written and read out by a pulse consisting of just a single optical oscillation with a duration of a few femtoseconds and an amplitude of ∼0.25 V/A.

For graphene interacting with a few-fs intense optical pulse, there is unique and rich behavior dramatically different from three-dimensional solids. Quantum electron dynamics is shown to be coherent but highly nonadiabatic and effectively irreversible due to strong dephasing. Electron distribution in reciprocal space exhibits hot spots at the Dirac points and oscillations whose period is determined by nonlocality of electron response and whose number is proportional to the field amplitude.

The strong ultrafast circularly polarized optical pulses can also be used to study an interferometry in graphene's reciprocal space without a magnetic field. The reciprocal space interferograms contain information on the electronic spectra and topological properties of graphene and on the waveform and circular polarization of the excitation optical pulses. These can be measured using angle-resolved photoemission spectroscopy with attosecond ultraviolet pulses.

While in quantum dots, i.e., flakes of two dimensional topological materials, the topology is not defined, the nonlinear electron dynamics in such zero dimensional systems results in generation of high optical harmonics.  The generation of high harmonics is strongly sensitive to the electron dephasing time and to the size and the shape of a quantum dot.

Biography

Vadym Apalkov is a professor of physics and astronomy at Georgia State University. He received his masters degree in physics from the Department of General and Applied Physics at Moscow Institute of Physics and Technology in 1991. He received his PhD from the University of Utah, Salt Lake City, Utah in 1995. His PhD research area was the Fractional Quantum Hall Effect. After receiving his PhD, he worked as a research scientist at Kharkov Institute of Physics and Technology. Then he was a postdoctoral research associate at the University of Utah till 2004. From 2004, he is a faculty member at the Department of Physics and Astronomy at Georgia State University. His research interests are transport and optical properties of low dimensional systems, such as graphene-like materials, quantum dots, Weyl semimetals, and others. He is also interested in spintronics and valleytronics in applications to information storage. Part of his research is also related to plasmonics and its applications.

Samer Gozem is an Associate Professor of Chemistry and Associate Director of Graduate Studies at Georgia State University. He obtained his B.Sc. in Chemistry in 2008 from the American University of Beirut in Lebanon and his Ph.D. in Photochemical Sciences in 2013 at Bowling Green State University. He then carried out his postdoctoral training at the University of Southern California before joining Georgia State University as a faculty member in 2017. His research interests include using classical and quantum mechanics to study light-responsive chemical and biological systems.

Moderated by Dr. Suranga Edirisinghe | ARCTIC at Georgia State University

Konstantin Cvetanov | Sr. Solution Architect – Enterprise AI Software
Konstantin Cvetanov is a Senior Solution Architect at NVIDIA focused on advancing the adoption of Artificial Intelligence software platforms in global Enterprise, Research, and Public Sector organizations. Before his 6 years at NVIDIA Konstantin spent much of his career in consulting roles leading multi-disciplinary Professional Services and Engineering teams at prominent Systems Integrators across major industries. During his career, Konstantin has published many blogs and manuals including a highly rated technical deployment book on Datacenter Virtualization and End User Computing featured on Amazon. Over the course of his career, Konstantin has cultivated a deep passion for youth career mentoring and loves fostering relationships with academic researchers and startup communities.

Brock Davis | Principal Engineering Manager – Microsoft
Brock Davis is a Principal Engineering Manager at Microsoft within the XBOX organization leading Gameplay Systems for Minecraft which focuses on everything from graphics rendering to using AI for pathfinding and Mob behaviors. Previously he has worked at Amazon Web Services, The Walt Disney Company, WarnerBros Discovery, and Georgia State University. While at Amazon, he led the Commercial Linux team for EC2 which was responsible for the underlying Linux images for AWS. At The Walt Disney Company, he focused on the cloud infrastructure for all of Disney Streaming products such as Disney+ and Hulu. At WarnerBros Discovery, he led efforts around personalization experiences and data privacy, as well as app development for Bleacher Report and CNN. At Georgia State University, he led the Research Solutions team that focused on providing solutions for funded research ranging from custom app development to compute. Through all of his roles he has gained extensive industry knowledge on app development, cloud computing, machine learning, and artificial intelligence.

Dr. Jennifer Esposito | Chair of Educational Policy Studies, Georgia State University
Jennifer Esposito is a department chair of Educational Policy Studies and a Distinguished University Professor at Georgia State University. Her research takes an intersectional approach to educational research, centering race and gender. As an interdisciplinary scholar, she sees critical theories as tools to interrogate social life and solve problems related to the material consequences of oppression and privilege.

Scott Kent | Principal of the FCS Innovation Academy

Dr. Renata Rawlings-Goss | Executive Director - The South Big Data Innovation Hub
Dr. Renata Rawlings-Goss is the Executive Director of The South Big Data Innovation Hub, an NSF-funded 16 state center connecting industry, academia, and government around data science innovation. She is the Director of Strategic Partnerships for the Georgia Institute of Technology- Institute for Data Engineering and Science (IDEaS), and also the founder of Good with Data LLC, which runs The Data Career Academy - for professionals and faculty looking to accelerate their careers with data.Formerly, Dr. Rawlings-Goss worked with the White House Office of Science and Technology Policy founding the National Data Science Organizers and co-leading the writing team for the Federal Big Data Strategic Plan. Through her roles, she has served as an executive strategist, career mentor, and policy advisor to Fortune 500 companies, individuals, as well as over 19 federal and state government agencies around data science education, Big Data, Digital Transformation, Public-Private Partnerships, Artificial Intelligence (AI), Internet of Things (IoT), Machine Learning, Data Career Success, Professional Development and Data Innovation. Dr. Renata Rawlings-Goss is a biophysicist by training and a nationally recognized leader in Data Science.Author of “Data Careers, Training, and Hiring” published in 2019 by SpringerPress, her work across fields has been recognized in the Washington Post, the Wall Street Journal, and as one of President Obama’s Top 100 Impacts in Science and Technology.

Biography

https://poloclub.github.io/polochau/