Reconstruction-Induced <i>φ</i><sub>0</sub> Josephson Effect in Quantum Spin Hall Constrictions

oleh: Lucia Vigliotti, Fabio Cavaliere, Giacomo Passetti, Maura Sassetti, Niccolò Traverso Ziani

Format: Article
Diterbitkan: MDPI AG 2023-04-01

Deskripsi

The simultaneous breaking of time-reversal and inversion symmetry, in connection to superconductivity, leads to transport properties with disrupting scientific and technological potential. Indeed, the anomalous Josephson effect and the superconducting-diode effect hold promises to enlarge the technological applications of superconductors and nanostructures in general. In this context, the system we theoretically analyze is a Josephson junction (JJ) with coupled reconstructed topological channels as a link; such channels are at the edges of a two-dimensional topological insulator (2DTI). We find a robust <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mi>φ</mi><mn>0</mn></msub></semantics></math></inline-formula> Josephson effect without requiring the presence of external magnetic fields. Our results, which rely on a fully analytical analysis, are substantiated by means of symmetry arguments: Our system breaks both time-reversal symmetry and inversion symmetry. Moreover, the anomalous current increases as a function of temperature. We interpret this surprising temperature dependence by means of simple qualitative arguments based on Fermi’s golden rule.