# Low-field Topological Threshold in Majorana Double Nanowires

## TL;DR

This paper demonstrates that in double nanowire systems, destructive interference can lower the magnetic field threshold for topological states, enabling the realization of Majorana bound states suitable for quantum computing.

## Contribution

It introduces a method to reduce the topological threshold in double nanowires via interference effects, facilitating experimental realization of Majorana states.

## Key findings

- Topological threshold can be reduced to experimentally accessible magnetic fields.
- Majorana bound states have short localization lengths, suitable for braiding.
- Interference effects enable control over topological phase transition.

## Abstract

A hard proximity-induced superconducting gap has recently been observed in semiconductor nanowire systems at low magnetic fields. However, in the topological regime at high magnetic fields, a soft gap emerges and represents a fundamental obstacle to topologically protected quantum information processing with Majorana bound states. Here we show that in a setup of double Rashba nanowires that are coupled to an s-wave superconductor and subjected to an external magnetic field along the wires, the topological threshold can be significantly reduced by the destructive interference of direct and crossed-Andreev pairing in this setup, precisely down to the magnetic field regime in which current experimental technology allows for a hard superconducting gap. We also show that the resulting Majorana bound states exhibit sufficiently short localization lengths, which makes them ideal candidates for future braiding experiments.