One of the most promising approaches of generating spin- and energy-entangled electron pairs is splitting a Cooper pair into the metal through spatially separated terminals. Utilizing hybrid systems with the energy-dependent barriers at the supercond
uctor-normal metal interfaces, one can achieve practically 100% efficiency outcome of entangled electrons. We investigate minimalistic one-dimensional model comprising a superconductor and two metallic leads and derive an expression for an electron-to-hole transmission probability as a measure of splitting efficiency. We find the conditions for achieving 100% efficiency and present analytical results for the differential conductance and differential noise.
The charge of the subgap states in an Andreev quantum dot (AQD; this is a quantum dot inserted into a superconducting loop) is very sensitive to the magnetic flux threading the loop. We study the sensitivity of this device as a function of its parame
ters for the limit of a large superconducting gap. In our analysis, we account for the effects of a weak Coulomb interaction within the dot. We discuss the suitability of this setup as a device detecting weak magnetic fields.
