CPM Seminar

Josephson Detection of Multiband Effects in Superconductors

James Williams

University of Maryland

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. In this talk I will detail the use of Josephson effect to detect novel properties of two multiband superconductors: NbSe₂ [1] and SnTe [2]. 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.

[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).