Hanno Weitering : Microscopic Fingerprint of Chiral Superconductivity. 

Chiral superconductors are anticipated to break time-reversal symmetry and host unconventional pairing states with topological characteristics, including Majorana excitations and spontaneous edge currents. Nevertheless, despite several promising material platforms, direct microscopic evidence of chiral pairing has remained elusive. In this work, we present combined experimental and theoretical results that establish definitive signatures of chiral superconductivity in a single atomic layer of tin on Si(111).1 This triangular-lattice, single-band system becomes superconducting upon hole doping, with a critical temperature of up to 9 K, thereby representing the thinnest and most dilute superconductor identified to date.2 Through quasiparticle-interference imaging, we resolve symmetry-locked nodal and antinodal structures in the Bogoliubov quasiparticle wavefunctions, localized at atomic-scale point defects and forming a characteristic real-space pattern uniquely attributable to chiral pairing.1 Supported by analytical theory and corroborated by numerical simulations, these observations constitute unambiguous, spatially resolved evidence for chiral superconductivity in a two-dimensional material. The structural simplicity and controllability of this surface-based platform provide a robust avenue for elucidating unconventional pairing mechanisms and for exploring topological superconducting phases in engineered quantum systems.

1 X. Wu et al., https://arxiv.org/abs/2507.18693

2 F. Ming et al., Nature Phys. 19, 500-506 (2023)