# Enhancement of crossed Andreev reflection in a Kitaev ladder connected to normal metal leads

## TL;DR

This paper investigates how a phase difference in a two-leg Kitaev ladder enhances crossed Andreev reflection, with subgap states causing oscillations in transconductance due to Fabry-Pérot resonance.

## Contribution

It demonstrates the enhancement of crossed Andreev reflection in a Kitaev ladder through phase tuning, revealing the role of subgap states and resonance effects.

## Key findings

- Crossed Andreev reflection can be significantly enhanced by phase difference tuning.
- Subgap states induce oscillations in transconductance related to system parameters.
- Fabry-Pérot resonance explains oscillatory behavior in the system.

## Abstract

We study nonlocal transport in a two-leg Kitaev ladder connected to two normal metals. The coupling between the two legs of the ladder when the legs are maintained at a (large) superconducting phase difference, results in the creation of subgap Andreev states. These states in turn are responsible for the enhancement of crossed Andreev reflection. We find that tuning the different parameters of the system suitably leads to enhancement of crossed Andreev reflection signalled by transconductance acquiring the most negative value possible. Furthermore, subgap states cause oscillations of the transconductance as a function of various system parameters such as chemical potential and ladder length, which are seen to be a consequence of Fabry-P\'erot resonance.