Quantum Monte Carlo study of static potential in graphene

TL;DR

This study uses quantum Monte Carlo methods to analyze the static interaction potential in suspended graphene, revealing that many-body effects lead to dielectric permittivity values close to one-loop predictions, with significant deviations from two-loop results.

Contribution

First quantum Monte Carlo calculation of dielectric permittivity in suspended graphene, highlighting the importance of many-body effects and higher-order corrections.

Findings

Dielectric permittivity at zero distance is approximately 2.24.

Permittivity reaches about 4.20 at large distances.

Many-body effects cause permittivity to align with one-loop predictions, deviating from two-loop estimates.

Abstract

In this paper the interaction potential between static charges in suspended graphene is studied within the quantum Monte Carlo approach. We calculated the dielectric permittivity of suspended graphene for the set of temperatures and extrapolated our results to zero temperature. The dielectric permittivity at zero temperature has the following properties. At zero distance $\epsilon=2.24\pm0.02$. Then it rises and at a large distance the dielectric permittivity reaches the plateau $\epsilon\simeq4.20\pm0.66$. The results obtained in this paper allow to draw a conclusion that full account of many-body effects in the dielectric permittivity of suspended graphene gives $\epsilon$ very close to the one-loop results. Contrary to the one-loop result, the two-loop prediction for the dielectric permittivity deviates from our result. So, one can expect large higher order corrections to the two-loop prediction for the dielectric permittivity of suspended graphene.