1999/12/20 by Joachim Wilke, J. Wilke, A. D. Mirlin +5 · 28 citations
Mathematics · Physics and Astronomy · #Anomaly (physics) #Boltzmann constant #Condensed matter physics #Electron #Magnetic field #Mathematical analysis #Mathematical physics #Mathematics #Mean free path #Omega #Physics #Quantum and electron transport phenomena #Quantum many-body systems #Quantum mechanics #Sign (mathematics) #Theoretical and Computational Physics #Zero (linguistics) #cond-mat.dis-nn #cond-mat.mes-hall
paper · pdf · doi:10.1103/physrevb.61.13774
published in Physical review. B, Condensed matter 61(20), 13774-13784 (American Physical Society) · 12 pages, RevTeX, 7 figures
arxiv created 1999/12/20 · openalex publication_date 2000/05/15 · arxiv updated 2009/11/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We study the low-frequency behavior of the ac conductivity \ensuremathσ(\ensuremathω) of a two-dimensional fermion gas subject to a smooth random potential (RP) or random magnetic field (RMF). We find a nonanalytic \ensuremath∝|\ensuremathω| correction to Re\ensuremathσ, which corresponds to a 1/t2 long-time tail in the velocity correlation function. This contribution is induced by return processes neglected in Boltzmann transport theory. The prefactor of this |\ensuremathω| term is positive and proportional to (d/l)2 for the RP, while it is of opposite sign and proportional to d/l in the weak RMF case, where l is the mean free path and d the disorder correlation length. This nonanalytic correction also exists in the strong RMF regime, when the transport is of a percolating nature. The analytical results are supported and complemented by numerical simulations.