The Fall 2021 MatSE 590 for graduate students consists of an exciting and jam-packed schedule. MATSE 590 is a colloquium (1-3 credits) consist of a series of individual lectures by faculty, students, or outside speakers.
Graduate students will receive a weekly email with information via @psu.edu email. Graduate students are required to attend all 590 Seminars. If you have any questions, please email Hayley Barnes at hjc24@psu.edu.
*Due to the ongoing Covid Pandemic this program is being offered virtually through Zoom. Please reference the weekly email from Hayley Barnes (hjc24@psu.edu) for Zoom link.
Thursday, November 4, 2021
“Atomic-scale Control of Emergent Properties at Complex Oxide Interfaces”
Divine Kumah, Associate Professor, Department of Physics, North Carolina State University
Abstract
The intricate interplay between charge, spin, orbital and structural de-grees of freedom at transition metal complex oxide (TMCO) interfaces has led to the discovery of a plethora of exciting phenomena including interfacial superconductivity, high mobility two-dimensional electron gases (2DEG) and interfacial magnetism. The manipulation of these emergent properties is of great interest due to potential applications ranging from spintronics and orbitronics to photonics. In this talk, a combination of atomic-scale materials synthesis, synchrotron X-ray high-resolution diffraction and spectroscopy, temperature-dependent transport and magnetometry, high-resolution electron microscopy and first-principles density functional theory are used to elucidate the inter-play between structural and electronic degrees of freedom at TMCO interfaces.
To illustrate the intimate link between interface-driven atomic-scale distortions and the physical properties of low-dimensional systems, this talk will focus on understanding the role epitaxial strain and interfacial and surface reconstructions play in stabilizing ferromagnetism in quasi-two dimensional transition metal oxide layers and high-mobility con-ductivity at the interfaces between polar and non-polar insulating ox-ides.[1,2,3]
These results demonstrate the strong correlation between the atomic-scale structural properties of 2D materials and their electronic and mag-netic ground phases with important implications for the atomic-scale design of the next generation of quantum materials.
Biographical Information
Divine Kumah is an Associate Professor in the department of Physics at North Carolina State University. He received his Ph.D. in Applied Physics from the University of Michigan in 2009 and did postdoctoral research at the Center for Research in Interface and Surface Phenomena at Yale University. His research interests are in experimental condensed matter physics and are aimed at understanding the novel properties which emerge at the interfaces between crystalline materials.
The Kumah Research Group at NC State uses state of the art atomic layer-by-layer deposition techniques in-cluding molecular beam epitaxy to fabricate thin crystalline oxide films. The group is focused on understand-ing how atomic-scale structural distortions at interfaces can be manipulated to induce novel electronic and magnetic phenomena and the development of pathways for harnessing these unique functionalities for elec-tronic and energy applications. Tools used by the group include atomic force microscopy, electron diffraction and synchrotron-based x-ray spectroscopy and diffraction.
