Supercurrent Control in Josephson Junctions

The control of supercurrent in Josephson Junction is a topic of immense interest because of its applications in superconducting and quantum computing devices, such as superconductor transistors and quantum qubits. The control of supercurrent using ferromagnetic materials, nanostructures with external magnetic and electric fields as the coupling region between two superconducting contacts have been either demonstrated or proposed. Recently some studies show that the spin-orbit interaction in the semiconducting coupling region of a Josephson junction can provide effective control of the supercurrent. The use of spin-orbit interaction in the control offers the following advantages over the other approaches: high flexibility, compact device structures and possible integration with semiconductor or spintronic devices. At the moment, the understanding of how the supercurrent is controlled using the spin-orbit interaction is quite limited. The present project aims to study the underlying physics of this phenomonon for the development of useful superconducting or quantum computing devices. The knowledge obtained in this project advances our understanding of not only superconducting devices, but also the phenomenon of triplet superconductivity.