Microscopic Fingerprint of Chiral Superconductivity

TL;DR

This paper provides direct real-space evidence of chiral superconductivity in a single atomic layer of tin on Si(111), revealing symmetry-locked quasiparticle features that confirm the presence of chiral pairing.

Contribution

It presents the first microscopic, real-space signatures of chiral superconductivity in a 2D material, combining experimental quasiparticle interference imaging with theoretical analysis.

Findings

Detection of symmetry-locked nodal and antinodal points in quasiparticle wavefunctions

Identification of a distinct real-space pattern as a hallmark of chiral superconductivity

Unambiguous evidence of chiral pairing in a two-dimensional material

Abstract

Chiral superconductors have long been theorized to break time-reversal symmetry and support exotic topological features such as Majorana modes and spontaneous edge currents, promising ingredients for quantum technologies. Although several unconventional superconductors may exhibit time-reversal symmetry breaking, clear microscopic evidence of chiral pairing has remained out of reach. In this work, we demonstrate direct real-space signatures of chiral superconductivity in a single atomic layer of tin on Si(111). Using quasiparticle interference imaging, we detected symmetry-locked nodal and antinodal points in the Bogoliubov quasiparticle wavefunction, tightly bound to atomic point defects in the tin lattice. These nodal features, along with their surrounding texture, form a distinct real-space pattern exhibiting a clear and exclusive hallmark of chiral superconductivity. Our findings, reinforced by analytical theory and numerical simulations, offer unambiguous evidence of chiral pairing in a two-dimensional material.