2025/11/03 by Oliver Franke, Franke, Oliver, Paula Koll +5
Physics and Astronomy · #FOS: Physical sciences #Magnetic properties of thin films #Mesoscale and Nanoscale Physics (cond-mat.mes-hall) #Quantum and electron transport phenomena #Topological Materials and Phenomena
paper · pdf · doi:10.48550/arxiv.2511.01806
openalex publication_date 2025/11/03 · openalex created_date 2025/11/06 · openalex updated_date 2026/07/31
The exchange coupling of the helical edge state of a quantum spin-Hall insulator with an easy-plane magnet has no effect on its DC electrical conductance if the magnet's anisotropy axis is aligned with the spin quantization axis of the helical edge state [Meng et al., Phys. Rev. B 90, 205403 (2014)]. We here calculate the AC conductance GV(ω) and the noise power SV(ω) in the presence of a DC bias V. While both take the universal values GV(ω= 0) = e2/h and SV(ω= 0) = 4 e2 k\rm B T/h in the zero-frequency limit, GV(ω) and SV(ω) are quickly suppressed for finite ω, so that low-frequency transport is effectively noiseless.