2018/10/31 by Fariborz Parhizgar, Annica M. Black‐Schaffer, Annica M. Black-Schaffer · 1 citation
Chemistry · Materials Science · Physics and Astronomy · #Band gap #Chemistry #Condensed matter physics #Cooper pair #Electrical engineering #Iron-based superconductors research #Josephson effect #Pairing #Physics #Physics of Superconductivity and Magnetism #Pi Josephson junction #Polarization (electrochemistry) #Semimetal #Spin (aerodynamics) #Superconductivity #Topological Materials and Phenomena #Topology (electrical circuits) #cond-mat.supr-con
paper · pdf · doi:10.1038/s41535-020-0244-2
published as npj Quantum Materials (2020) 5:42 · 4 figures + 11 supplementary figures
openalex publication_date 2020/06/25 · arxiv created 2020/07/17 · arxiv updated 2020/07/20 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/06
Abstract Weyl nodal loop semimetals (WNLs) host a closed nodal line loop Fermi surface in the bulk, protected zero-energy flat band, or drumhead, surface states, and strong spin-polarization. The large density of states of the drumhead states makes WNL semimetals exceedingly prone to electronic ordering. At the same time, the spin-polarization naively prevents conventional superconductivity due to its spin-singlet nature. Here we show the complete opposite: WNLs are extremely promising materials for superconducting Josephson junctions, entirely due to odd-frequency superconductivity. By sandwiching a WNL between two conventional superconductors we theoretically demonstrate the presence of very large Josephson currents, even up to orders of magnitude larger than for normal metals. The large currents are generated both by an efficient transformation of spin-singlet pairs into odd-frequency spin-triplet pairing by the Weyl dispersion and the drumhead states ensuring exceptionally proximity effect. As a result, WNL Josephson junctions offer unique possibilities for detecting and exploring odd-frequency superconductivity.