Dr. Maksymovych is Professor of Materials Science and Engineering at Clemson University. Prior to Clemson, he was a Distinguished Staff Scientist at Oak Ridge National Laboratory and a Theme Leader at the Center for Nanophase Materials Sciences. His research is aimed at noncentrosymmetric materials and their phase transitions, enabling new electronic and optoelectronic materials that leverage topological defects and non-linear dynamics (nanosparq.github.io). He joined ORNL as the Eugene P. Wigner Fellow in 2007, with the focus on intersection of structural topology and electronic transport for neuromorphic computing. He subsequently investigated superconductivity on a molecular lattice and discovered new ferroelectric properties of ternary van der Waals materials. He also developed several nanoscale imaging techniques, such as tunneling thermometry and Andreev tunneling microscopy. He authored over 140 peer reviewed publications, 4 book chapters, six patents and received several national awards. He is a regular organizer of workshops on physics and applications of nanomaterials, including the Fundamental Physics of Ferroelectrics and Related Materials (in 2019 and 2020) and the symposium dedicated to neuromorphic computing Nano4Neuro (2022-2026). He also serves as the Chair of the Tennessee Valley Chapter of the American Vacuum Society, whose mission is promoting the multidisciplinary topics of materials science, space and information materials to research and applied schools across the South-East.
Presentation Title:
Atomic-Scale Andreev Sensing for Quantum Materials
Presentation Abstract:
Pairing quantum sensing with atomic resolution enables microscopy inaccessible to classical probes. Nitrogen-vacancy magnetometry is the paradigmatic example, yet true atomic resolution remains an open challenge. Andreev reflection, the coherent conversion of a quasiparticle into a Cooper pair at a metal-superconductor interface, is a phase-coherent electron-hole scattering process that is natively compatible with atomic-scale tunneling geometry. However, its use as an atomic-scale probe has also advanced slowly: point-contact methods sacrifice atomic resolution for mechanical contact, while tunneling spectroscopy conflates Andreev and quasiparticle currents. We introduced a new observable, the excess tunneling decay rate, that cleanly disentangles conductance channels in a metal-superconductor tunnel junction (Nano Lett. 23 (2023) 8310, arXiv:2601.20798). This observable revealed coherent signatures of pairing symmetry and higher-order Andreev processes, establishing tunneling Andreev reflection as an atomic-scale sensor for conventional, unconventional and topological superconductors. Research supported by Clemson University and Basic Energy Sciences Division of the Department of Energy.