Novel non-local effects in three-terminal hybrid devices with quantum dot

TL;DR

This paper predicts strong, tunable non-local effects in a three-terminal hybrid device with a quantum dot, driven by competition between ballistic transfer and crossed Andreev scattering, with potential implications for quantum transport control.

Contribution

It introduces a novel understanding of non-local effects in quantum dot hybrid devices involving superconductors, highlighting the roles of Shiba states and long-range interactions.

Findings

Non-local voltage can be controlled by gate potential and coupling strength.

Effects are robust in both linear and non-linear regimes.

Compared to planar junctions, effects are significantly stronger.

Abstract

We predict strong non-local effects in the three-terminal hybrid device, comprising the quantum dot embedded between two conducting leads and third superconducting reservoir. They result from competition between the ballistic electron transfer and the crossed Andreev scattering. The non-local voltage induced in response to the 'driving' current changes the magnitude and sign upon varying the gate potential and/or coupling to the superconducting lead. Such effect is robust both in the linear and non-linear regimes, where the screening and the long-range interactions play significant role. This novel subgap transport is provided by the Shiba states and can be contrasted with much weaker non-local effects observed hitherto in the three-terminal 'planar' junctions.