2004/06/02 by Sangchul Oh, Jaewan Kim · 1 citation
Computer Science · Physics and Astronomy · #Physics of Superconductivity and Magnetism #Quantum Information and Cryptography #Quantum and electron transport phenomena #cond-mat.mes-hall #quant-ph
paper · pdf · doi:10.1103/physrevb.71.144523
published as Physical Review B 71, 144523 (2005) · 4 pages, 2 eps figures
arxiv created 2004/06/02 · openalex publication_date 2005/04/29 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We investigate entanglement of two electron spins forming Cooper pairs in an s-wave superconductor. The two-electron space-spin density matrix is obtained from the BCS ground state using a two-particle Green's function. It is demonstrated that a two spin state is not given by a spin singlet state but by a Werner state. It is found that the entanglement length, within which two spins are entangled, is not of the order of the coherence length but of the order of the Fermi wave length.