Work

Finite-frequency admittance and noise of a helical edge coupled to a magnet

Year: 2025

Type: article

Abstract: 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 , ]. We here calculate the ac conductance G V ( ω ) and the noise power S V ( ω ) in the presence of a dc bias V . While both take the universal values G V ( ω = 0 ) = e 2 / h and S V ( ω = 0 ) = 4 e 2 k B T / h in the zero-frequency limit, G V ( ω ) and S V ( ω ) are quickly suppressed for finite ω , so that low-frequency transport is effectively noiseless.

Source: Physical review. B./Physical review. B

DOI: 10.1103/yj56-jtxd

Authors: Oliver Franke, Paula Koll, Peter G. Silvestrov, Piet W. Brouwer

Institutions: Freie Universität Berlin, Technische Universität Braunschweig

Language: English

Topic: Topological Materials and Phenomena

Subfield: Atomic and Molecular Physics, and Optics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: hybrid

Funder: Deutsche Forschungsgemeinschaft

Awards: TRR 227: Ultraschnelle Spindynamik, G4846862643