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arXiv · 2505.01835

Friedel oscillations in a two-dimensional electron gas and monolayer graphene with a non-Coulomb impurity potential

Levente Máthé·Ioan Grosu
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Abstract

We study Friedel oscillations in a two-dimensional non-interacting electron gas and in a monolayer graphene in the presence of a single impurity. The potential generated by the impurity is modeled using a non-Coulomb interaction ($\sim r^{-\eta}$). The charge carrier density deviation as a function of distance from the impurity is calculated within the linear response theory. Our results show that, in both a two-dimensional non-interacting electron gas and graphene, the phase of charge carrier density oscillations remains unaffected by the parameter $\eta$, which characterizes the non-Coulomb nature of the interaction, at large distances from the impurity. The parameter $\eta$ influences only the amplitude of the oscillations in this regime. The results for an impurity modeled by Coulomb-like potential ($\eta = 1$) are recovered in both cases.

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Levente Máthé, Ioan Grosu. 2025-05-03. Friedel oscillations in a two-dimensional electron gas and monolayer graphene with a non-Coulomb impurity potential. https://doi.org/10.1016/j.physe.2025.116328

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