Spin and magnetic properties of superconducting tunnel junctions

• Applicant: Professor Dr. Jaroslav Fabian
• Subject Area: Theoretical Condensed Matter Physics
• Term: since 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 454646522

Superconducting tunnel junctions serve as excellent platforms for investigating the intricate physics arising from the interplay of spin interactions - spin-orbit and exchange coupling - and superconducting correlations. The recent discovery of the superconducting diode effect has spurred intensive research activity aiming to understand current-phase relation anomalies, such as the supercurrent rectification in the presence of magnetochirality, the emergence of phi0-phase shifts, and the possibility of associated topological superconductivity. In this proposal, we intend to investigate such effects in superconducting tunnel junctions that comprise noncollinear ferromagnets and interfacial spin-orbit coupling. Specifically, we will perform theoretical investigations of multi-component and noncollinear magnetic superconducting junctions, and their interference in triplet generation. We will also explore the role of triplet correlations in the superconducting diode effect. Developing reliable detection methods for triplet supercurrents is an outstanding issue. We will address this challenge by theoretically benchmarking novel detection schemes based on spin torque and Josephson-junction spin valves. Finally, we will explore novel Josephson Hall effect supercurrent transport in the presence of noncollinear magnetization and search for experimentally viable routes toward the detection of this elusive phenomenon. The theoretical investigations will be based on effective model systems as well as numerical simulations of realistic superconducting junctions.

• DFG Programme: Research Grants