Anomalous screening in two-dimensional materials with an extremum ring in the dispersion law

Abstract

A variety of two-dimensional materials possess a band structure with an energy extremal ridge along a ring in momentum space. Examples are biased bilayer graphene, and surfaces and interfaces with a Rashba spin-orbit interaction where at low doping the carriers fill an annulus. This topological feature causes an anomalous screening behavior, which we study using the Thomas-Fermi theory. Specifically, reducing the doping is predicted to enhance the linear screening response, while at zero doping the size of the screening cloud surrounding a Coulomb impurity is found to increase as the cube root of the impurity charge.

4+ pages, 1 figure, minor changes, version to be published in Phys. Rev. B

References in corpus (6)

• The electronic properties of graphene
• The electronic properties of bilayer graphene
• Nonlinear screening of charge impurities in graphene
• Screening of a hypercritical charge in graphene
• Low density ferromagnetism in biased bilayer graphene
• Mobile magnetic impurities in a Fermi superfluid: a route to designer molecules