The study of unconventional superconducting materials remains an active frontier of condensed matter physics. Exotic superconductivity, such as high T_C, topological, and heavy-fermion superconductors, often rely on phase sensitive measurements to determine the underlying pairing and/or the nature of novel excitations. Our group has recently been exploring multiband superconductivity in two superconductors: NbSe_2 [1] and SnTe [2]. In this talk focus be given to the modification of conventional Josephson effects due to the loss of time reversal symmetry found to exist in proximity-induced Josephson junction of SnTe nanowires [2]. Here we observe an interesting interplay between multiband effects and a ferroelectric transition. Each of these works open new routes to exploration of multiband effects in superconductors and have important implications for topological states in superconducting materials.

James Williams is currently the Alford Ward Assistant Professor of Physics in the Physics Department at the University of Maryland working in quantum material devices. He is also a Fellow at the Joint Quantum Institute and a member of the Center for Nanophysics and Advanced Materials at the university. He performed his Ph. D. at Harvard University, working on creating nanoscale devices from of graphene. Prior to coming to Maryland, he was the Karl van Bibber Postdoctoral Fellow in the Physics Department at Stanford University where he worked on quantum transport in topological insulators and superconductors.

Department of Physics Condensed Matter Seminar Series

1. S. Tran, J. Sell and J. R. Williams, “Dynamical Josephson Effects in NbSe2”, arXiv:1903.00453 (2019).
2. C. J. Trimble et al., “Josephson Detection of Time Reversal Symmetry Broken Superconductivity in SnTe Nanowires”, arXiv:1907.04199 (2019).

Researchers should cite this work as follows:

• James Williams (2020), "Josephson Detection of Multiband Effects in Superconductors," https://nanohub.org/resources/34093.

  BibTex | EndNote

1. condensed matter physics
2. Josephson effects
3. nanowires
4. superconducting materials
5. Superconductors
6. topological materials and matter