2013/02/18 by D. Schmeltzer, K. Ziegler, Schmeltzer, D. +1
Chemistry · Engineering · Physics and Astronomy · #Aerogels and thermal insulation #FOS: Physical sciences #Mesoscale and Nanoscale Physics (cond-mat.mes-hall) #Nanotechnology research and applications #Surface Roughness and Optical Measurements #cond-mat.mes-hall
paper · pdf · doi:10.48550/arxiv.1302.4145
arxiv created 2013/02/18 · openalex publication_date 2013/02/18 · arxiv updated 2013/02/19 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
The optical conductivity for the surface excitations for a Topological Insulator as a function of the chemical potential and disorder is considered. Due to the time reversal symmetry the chiral metallic surface states are protected against disorder. This allow to use the averaged single particle Green's function to compute the optical conductivity. We compute the conductivity in the limit of a finite disorder. We find that the conductivity as a function of the chemical potential μ and frequency Ω is given by the universal value σ(Ω>2μ)= (e2 π)/(8h). For frequencies Ω< μ and elastic mean free path lel=vτ which obey kFl>1 we obtain the conductivity is given by σ(Ω<2|μ|)=(e2)/(2h)\frackFlel(Ωτ)2+1. In the limit of zero disorder we find σ(μ≠0,Ω, kFl→ ∞)=(e2 π)/(2h)|μ|δ(Ω).