2004/01/31 by Sergei V. Sharov, S. V. Sharov, Andrei D. Zaikin · 11 citations
Materials Science · Physics and Astronomy · #Condensed matter physics #Electron #Iron-based superconductors research #Josephson effect #Parity (physics) #Physics #Physics of Superconductivity and Magnetism #Quantum #Quantum and electron transport phenomena #Quantum mechanics #Superconductivity #Supercurrent #cond-mat.mes-hall #cond-mat.supr-con
paper · pdf · doi:10.1103/physrevb.71.014518
published in Physical Review B 71(1) (American Physical Society) · Published version
openalex publication_date 2005/01/24 · arxiv created 2005/02/09 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We argue that at sufficiently low temperatures T superconducting parity effect may strongly influence equilibrium persistent currents (PCs) in isolated superconducting nanorings containing a weak link with few conducting modes. An odd electron, being added to the ring, occupies the lowest available Andreev state and produces a countercurrent circulating inside the ring. For a single channel quantum point contact at T=0 this countercurrent exactly compensates the supercurrent Ie produced by all other electrons and, hence, yields complete blocking of PCs for any value of the external magnetic flux. In superconducting nanorings with embedded normal metal the odd electron countercurrent can ``overcompensate'' Ie and a novel ``\ensuremathπ∕N-junction'' state occurs in the system. Changing the electron parity number from even to odd results in spontaneous supercurrent in the ground state of such rings without any externally applied magnetic flux.