Weyl-Superconductivity revealed by Edge Mode mediated Nonlocal Transport

TL;DR

This paper reports the first unambiguous observation of topologically protected edge modes in a Weyl superconductor, demonstrated through non-local transport measurements in FeTe_{0.55}Se_{0.45}, revealing potential for quantum computing and spintronics.

Contribution

It provides the first direct evidence of protected edge modes in a Weyl superconductor using non-local transport, confirming topological protection in FeTe_{0.55}Se_{0.45}.

Findings

Observation of resonant charge injection and ballistic transport via edge modes.

Emergence of an anomalous conductance plateau under specific phase coexistence.

Edge mode protection confirmed by insensitivity to magnetic fields and temperature.

Abstract

Topological superconductivity (TSC) hosts exotic modes enabling error-free quantum computation and low-temperature spintronics. Despite preliminary evidence of edge modes, unambiguous signatures remain undetected. Here, we report the first observation of protected, non-local transport from the edge modes of the potential Weyl-superconductor \ch{FeTe_{0.55}Se_{0.45}}. Namely resonant charge injection, ballistic transport, and extraction via edge modes. An anomalous conductance plateau emerges only when topological, superconducting, and magnetic phases coexist, with source-drain contacts coupled via the edge. Moving the drain to the bulk switches the non-local transport process to a local Andreev process, generating a zero-bias conductance peak (ZBCP). The edge mode's topological protection is confirmed by its insensitivity to external magnetic fields and increasing temperatures until the spontaneous magnetization is substantially suppressed. Our findings provide a new methodology to demonstrate TSC edge states in \ch{FeTe_{0.55}Se_{0.45}} via topologically protected non-local transport.