Quasi-bound states and resonant skew scattering in two-dimensional materials with a Mexican-hat dispersion

Mexican-hat dispersion of band electrons in two-dimensional materials attracts a lot interest, mainly due to the Van Hove singularity density states near edge. In this paper, we show that there is one more feature such dispersion, which also leads nontrivial effects. It consists fact sign effective mass momentum space central extremum opposite outside region. For reason, any localized potential repels quasiparticles outer region and thereby creates quasi-bound states. We study these case when formed hybridization inverted electron hole bands, created by point defect. The energy width resonance local corresponding state are found, it shown that, under certain conditions, can transform into bound continuum presence effects spin-dependent scattering electrons. Due state, skew strongly enhanced for with resonance, skewness angle varies over wide range depending on energy. addition, range, effect suppression appears direction angle.