2D skew scattering in the vicinity and away from resonant scattering condition

TL;DR

This paper investigates the energy dependence of 2D skew scattering from strong potentials, revealing a universal maximum shape, resonance effects, and temperature dependence related to the Kondo resonance.

Contribution

It provides an analytical description of skew scattering maxima and resonance effects in 2D systems with strong potentials, extending understanding beyond the Born approximation.

Findings

Skew scattering cross section has a maximum at intermediate energies.

Resonant enhancement occurs near quasilocal states with zero angular momentum.

Skew scattering exhibits sign reversal near certain resonances and shows strong temperature dependence due to Kondo effects.

Abstract

We studied the energy dependence of the 2D skew scattering from strong potential, for which the Born approximation is not applicable. Since the skew scattering cross section is zero both at low and at high energies, it exhibits a maximum as a function of energy of incident electron. We found analytically the shape of the maximum for an exactly solvable model of circular-barrier potential. Within a rescaling factor, this shape is universal for strong potentials. If the repulsive potential has an attractive core, the discrete levels of the core become quasilocal due to degeneracy with continuum. For energy of incident electron close to the quasilocal state with zero angular momentum, the enhancement of the net cross section is accompanied by resonant enhancement of the skew scattering. By contrast, near the resonance with quasilocal states having momenta $\pm 1$, the skew scattering cross section is an odd function of energy deviation from the resonance, and passes through zero, i.e., it exhibits a sign reversal. In the latter case, in the presence of the Fermi sea, the Kondo resonance manifests itself in strong temperature dependence of the skew scattering.