English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

We study the low-frequency behavior of the {\it ac} conductivity$\sigma(\omega)$ of a two-dimensional fermion gas subject to a smooth randompotential (RP) or random magnetic field (RMF). We find a non-analytic$\propto|\omega|$ correction to ${\rm Re} \sigma$, which corresponds to a$1/t^2$ long-time tail in the velocity correlation function. This contributionis induced by return processes neglected in Boltzmann transport theory. Theprefactor of this $|\omega|$-term is positive and proportional to $(d/l)^2$ forRP, while it is of opposite sign and proportional to $d/l$ in the weak RMFcase, where $l$ is the mean free path and $d$ the disorder correlation length.This non-analytic correction also exists in the strong RMF regime, when thetransport is of a percolating nature. The analytical results are supported andcomplemented by numerical simulations.Comment: 12 pages, RevTeX, 7 figure

physical review. b, condensed matter

Zero-frequency anomaly in quasiclassical ac transport: Memory effects in a two-dimensional metal with a long-range random potential or random magnetic field