${\Delta }_T$ Noise as a Robust Diagnostic for Chiral, Helical and Trivial Edge Modes

Abstract

In this article, we demonstrate that ${\Delta }_T$ noise provides a sensitive, practical probe for distinguishing chiral edge modes from topological helical and trivial (non-topological) helical edge transport. Measured under zero-current conditions, ${\Delta }_T$ noise reveals contrasts that conventional conductance measurements typically miss. Crucially, ${\Delta }_T$ noise requires no external energy input in the form of an applied voltage bias, yet encodes the same intrinsic information that shot noise yields in the zero-temperature, finite-bias limit, without the distorting effects of Joule heating. This absence of bias-induced heating makes ${\Delta }_T$ noise both more precise and more reliable than conventional shot-noise approaches.

25 pages, 11 figures, 2 Tables; accepted for publication in J. Phys.: Condens. Matter