Mats Jonson

University of Gothenburg, Sweden

5 October 2023 Thu 4 pm

                                      IBS Center for Theoretical Physics of Complex Systems (PCS), Administrative Office (B349), Theory Wing, 3rd floor

                                      Expo-ro 55, Yuseong-gu, Daejeon, South Korea, 34126 Tel: +82-42-878-8633                     

Controlling the flow of the charge and the spin of electrons is central to nanoscale electronics and spintronics. However, in conventional BCS superconductors the spins of Cooper-paired electrons are “locked” into a spin-singlet state, making the spin-degree of freedom “frozen out” for the purpose of spintronics applications. In this talk we will try to answer the question whether the spin degree of freedom could be “unlocked” in order to enable the spin- as well as the charge degree of freedom to take advantage of the macroscopic phase coherence of the superconducting BCS state. In particular we will describe how spin-dependent electron tunneling through a voltage-biased micro-constriction between two bulk superconductors can be a vehicle for  creating a static magnetization near the constriction as well as an ac  Josephson-like spin current, with possible implications for electrically controlled dissipation-less spintronics.

  1. magnetizing a bcs superconductor by spin-dependent tunneling