Magnetic field filtering of the hinge supercurrent in unconventional metal NiTe$_2$-based Josephson junctions

TL;DR

This study demonstrates that applying an in-plane magnetic field to NiTe$_2$-based Josephson junctions filters out bulk supercurrent, revealing hinge supercurrents associated with topological boundary states in an unconventional metal.

Contribution

It introduces a magnetic field filtering technique to isolate hinge supercurrents in NiTe$_2$-based Josephson junctions, highlighting the presence of obstructed hinge states in this topological material.

Findings

In-plane magnetic field suppresses bulk supercurrent in NiTe$_2$ JJs.

Hinge supercurrent persists under magnetic field, indicating boundary states.

Theoretical analysis confirms the unconventional and obstructed nature of hinge states.

Abstract

Topological materials with boundary (surface/edge/hinge) states have attracted tremendous research interest. Besides, unconventional (obstructed atomic) materials have recently drawn lots of attention owing to their obstructed boundary states. Experimentally, Josephson junctions (JJs) constructed on materials with boundary states produce the peculiar boundary supercurrent, which was utilized as a powerful diagnostic approach. Here, we report the observations of conspicuous hinge supercurrent in NiTe$_2$-based JJs. Particularly, applying an in-plane magnetic field along the Josephson current could rapidly suppress the bulk supercurrent and retain the nearly pure hinge supercurrent, namely the magnetic field filtering of supercurrent. Further systematic comparative analysis and theoretical calculations demonstrate the existence of unconventional nature and obstructed hinge states in NiTe$_2$. Our results revealed the unique hinge states in unconventional metal NiTe$_2$, and demonstrated in-plane magnetic field as an efficient method to filter out the futile bulk contributions and thereby to highlight the hinge states hidden in topological/unconventional materials.