Engineering high-purity crossed Andreev reflection by chiral Rashba matching
Phys. Rev. B 114, 105416 – Published 24 August, 2026
DOI: https://doi.org/10.1103/t3sd-h48t
Abstract
We show a high-purity crossed Andreev reflection (CAR) in a fully nonmagnetic junction, which features a superconductor layer sandwiched between two leads with gate-tunable opposing Rashba fields. A scattering matrix method is developed to quantify the high-purity CAR by calculating the full scattering processes comprising reflection and transmission. The underlying mechanism, which we term chiral Rashba matching, leverages the mutually exclusive opposite spin textures in the two leads to suppress nonlocal electron cotunneling (CT) while enhancing CAR. Remarkably, we show that the high-purity CAR can be switched on/off as desired via tuning either the Fermi level or the driving bias. Our proposed all-electrical, magnetic-element-free scheme for CAR enables simpler and more scalable architectures for on-chip quantum entanglement generation.
