Asymmetric features in the resistivity of clean quasi-one-dimensional systems: Fano resonances or non-Born effects?
A. S. Ioselevich+*, N. S. Peshcherenko×° 1)
+Condensed-matter physics laboratory, National Research University Higher School of Economics, 101000 Moscow, Russia
*L.D. Landau Institute for Theoretical Physics, 119334 Moscow, Russia
×Skolkovo Institute of Science and Technology, 121205 Moscow, Russia
°Moscow Institute of Physics and Technology, 141700 Moscow, Russia
Abstract
We show that experimentally observed complex line shapes of smeared Van
Hove singularities in the resistivity of a quasi-one-dimensional system
may be due to non-Born effects in scattering. At low concentration of
impurities with respect to scattering amplitude
λ the non-Born effects are essential if the Fermi level is
sufficiently close to singularity. The structure of the line shape
depends on the sign of λ: for repulsion (λ>0) it is
"plateau-minimum-maximum-plateau", while for attraction
(λ<0) it is "plateau-maximum-minimum-maximum-plateau". In
contrast with Fano-resonance scenario, complex structure of the line
shape arises even in the absence of a resonant level.