# Edge dependent Josephson Diode effect in WTe$_{2}$-Based Josephson junction

## TL;DR

This paper theoretically demonstrates a significant Josephson diode effect in WTe$_{2}$-based junctions, driven by asymmetric edge states and tunable via chemical potential, offering a promising route for dissipationless electronics.

## Contribution

It reveals how intrinsic edge asymmetry in WTe$_{2}$ can produce a strong JDE, and shows how tuning the chemical potential enhances diode efficiency beyond 50%.

## Key findings

- Edge asymmetry in WTe$_{2}$ induces JDE.
- Chemical potential tuning boosts efficiency over 50%.
- JDE remains robust against moderate edge disorder.

## Abstract

The Josephson diode effect (JDE), a nonreciprocal supercurrent, is a cornerstone for future dissipationless electronics, yet achieving high efficiency in a simple device architecture remains a significant challenge. Here, we theoretically investigate the JDE in a junction based on monolayer 1T'-WTe$_2$. We first establish that different edge terminations of a WTe$_2$ nanoribbon lead to diverse electronic band structures, some of which host asymmetric edge states even with crystallographically equivalent terminations. This intrinsic asymmetry provides a natural platform for realizing the JDE. With a WTe$_2$-based Josephson junction, we demonstrate a significant JDE arising purely from these asymmetric edges when time-reversal symmetry is broken by a magnetic flux. While the efficiency of this edge-state-driven JDE is inherently limited, we discover a crucial mechanism for its enhancement: by tuning the chemical potential into the bulk bands, the interplay between edge and bulk transport channels boosts the maximum diode efficiency more than $50\%$. Furthermore, we show that this enhanced JDE is robust against moderate edge disorder. Our findings not only propose a novel route to achieve a highly efficient JDE using intrinsic material properties but also highlight the potential of engineered WTe$_2$ systems for developing advanced superconducting quantum devices.