Electron Entanglement in Composite BSCCO nanowires

Composite super/normal conducting structures provide a source of entangled electrons that result from the formation of electron-hole quasibound states in the composite structures. One signature of the electron entanglement is the existence of positive cross-correlated shot noise in the electron currents that are emitted from the nanowires. Positive shot noise is an indicator that Bell’s inequality has been violated and that electrons in the emitted electron current are entangled. We have shown that a (NS)^nN nanowire, with ballistic normal (N) segments and BSCCO superconducting (S) segments, can provide a significant source of entangled electrons. The existence of entangled electrons can also be seen in the structure of bi-partite reduced density matrix for the composite structure. Changes in the bi-partite reduced density matrix track the behavior of the shot noise and gives additional information about parameter regimes that give rise to entangled electrons.

1. C. Ostrove and L.E. Reichl, Physica B, 561, 79 (2019); Phys. Rev. B, 103, 224518 (2021).
   
   L.E. Reichl, Physica B, 586, 412114 (2020); 628, 413598 (2022).
   
   L.E. Reichl and F. Estrella, “Electron Entanglement in Composite BSCCO nanowires,” (In preparation).