The origin of a mysterious experimental observation in a superconductor with a magnetic impurity sitting on top of it has been revealed in a theoretical study by a RIKEN researcher and a collaborator. This could help realize a robust quantum state residing in a superconductor that may find application in quantum computers.

Superconductors conduct electricity without any resistance because electrons in them form pairs that have an energy gap. But placing a magnetic atom on top of a superconductor creates a new state in this energy gap as a result of the atom’s magnetism interacting with the superconductor’s paired electrons.

Known as the Yu–Shiba–Rusinov state, or Shiba state for short, this state has been attracting a lot of interest because it could shed light on the emergence of a special state in a topological superconductor called the Majorana zero mode, which is promising for realizing fault-tolerant quantum computing.

To read more, please visit the related link.


  1. Ching-Kai Chiu and Ziqiang Wang, Yu-Shiba-Rusinov States in a Superconductor with Topological Z 2 Bands, Phys. Rev. Lett. 128, 237001 (2022), doi: 10.1103/PhysRevLett.128.237001