Polarizability and impurity screening for phosphorene

TL;DR

This paper calculates the dielectric response and impurity screening in phosphorene using a tight-binding model, revealing directional dependence at large momentum transfers and temperature effects.

Contribution

It provides a detailed analysis of the polarizability and dielectric function of phosphorene, including temperature effects and impurity screening, which advances understanding of its electronic properties.

Findings

Dielectric function depends on direction for large momentum transfer.

Screening behavior varies with temperature, from 0K to 300K.

Results align with previous studies but extend to impurity screening analysis.

Abstract

Using a tight-binding Hamiltonian for phosphorene, we have calculated the real part of the polarizability and the corresponding dielectric function, Re$[\epsilon(\textbf{q},\omega)]$, at zero temperature (T = 0) with free carrier density $10^{13}$/ $cm^2$. We present results showing the real part of dielectric function in different directions of the transferred momentum $\bf{q}$. When $q$ is larger than a particular value which is twice the Fermi momentum $k_F$, Re$[\epsilon(\textbf{q},\omega)]$ becomes strongly dependent on the direction of $\bf{q}$. We also discuss the case at room temperature (T = 300K). These results which are similar to those previously reported by other authors are then employed to determine the static shielding of an impurity in the vicinity of phosphorene.