Friday, May 5
2:00-2:30 p.m. 

“Material Searches and Designs of Topological Superconductors”

Abstract

Quantum phases of matter known as superconductors can transmit electrical current with zero resistance. While many metals in everyday life are known to become superconductors at ultra-low temperatures, a special kind of superconductors called ‘topological superconductors’ (Tsc) have attracted widespread attention in the past two decades for being predicted as promising platforms for fault-tolerant quantum computation. A key challenge in the field, however, has been the rareness of material realization of Tsc.

In this talk, I will discuss guiding principles for material designs of Tsc candidates as well as strategies for thorough searches in material databases, using approaches ranging from topology analyses, model building, to machine learning. I will also discuss explicit examples of predicted candidates in the family of transition metal dichalcogenides. 

Biography

Yi-Ting Hsu joined the College of Science at the University of Notre Dame as an assistant professor in the Department of Physics and Astronomy in 2020. Prior to this, she worked as a postdoctoral research associate in the Condensed Matter Theory Center at the University of Maryland. She received her Ph.D. with Prof. Eun-Ah Kim from Cornell University and her B.S. from National Tsing Hua University in Taiwan. Hsu is also a recent recipient of an NSF CAREER Award to support theoretical research and education with the aim to identify and design superconducting materials that possess a new state of matter, topological superconductors. 

Her research interests lie in theoretical studies of emergent phenomena in quantum many-body systems driven by intertwined symmetries, topology, and interactions. She aims to understand and characterize new phases of matter emerging from such systems, as well as to search for their realizations. Particular topics include: (1) topological phases protected by crystalline symmetries, (2) unconventional superconductivity, (3) correlated phases in van der Waals materials (including moire systems), (4) dynamical phases in isolated quantum systems, and (5) machine-learning application to condensed matter problems.

Selected Publications

1. S.-J. Huang and Y.-T. Hsu, "Faithful derivation of symmetry indicators: A case study for topological superconductors with time-reversal and inversion symmetries", Phys. Rev. Research 3(2021) 013243
2. Y.-T. Hsu, W. S. Cole, R.-X. Zhang, J. D. Sau, “Inversion-protected topological crystalline superconductivity in monolayer WTe$_2$”, Phys. Rev. Lett. 125 (2020) 097001
3. Y.-T. Hsu, F. Wu, S. Das Sarma, “Topological superconductivity, ferromagnetism, and valley-polarized phases in moire systems: Renormalization group analysis for twisted double bilayer graphene”, Phys. Rev. B 102 (2020) 085103 (Editor’s suggestion)
4. Y.-T. Hsu, X. Li, D.-L. Deng, S. Das Sarma, “Machine learning many-body localization: Search for the elusive nonergodic metal”, Phys. Rev. Lett. 121 (2018) 245701
5. Y.-T. Hsu, A. Vaezi, M. H. Fischer, E.-A. Kim, “Topological superconductivity in monolayer transition metal dichalcogenides”, Nat. Comm. 8 (2017) 14985

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