Non-perturbative corrections to the quasiparticle velocity in graphene

TL;DR

This paper applies a non-perturbative approach to calculate corrections to the quasiparticle velocity in graphene, achieving better agreement with experiments and analyzing the stability of the renormalization group fixed point.

Contribution

It introduces a non-perturbative method to improve the theoretical prediction of quasiparticle velocity in graphene, aligning more closely with experimental data.

Findings

Non-perturbative corrections improve velocity predictions.

Better agreement with experimental measurements.

Infrared fixed point stability remains unchanged.

Abstract

Relativistic fermionic systems have physical quantities calculated by well stablished quantum electrodynamic prescriptions. In the last few years there has been an enormous interest in condensed matter systems in which the fermions exhibit relativistic dispersion, as Dirac fermions in graphene. We employ a non-perturbative method in order to obtain a non-perturbative correction to the quasiparticle velocity in graphene, and compare with the experimental data. We find a better agreement between the quasiparticle velocity corrected with non-perturbative corrections and measurements, when compared with the standard one-loop result. We also investigate the behavior of the beta function of the renormalization group theory, and find that the non-perturbative corrections do not alter the stability of the infrared fixed point found by the standard result.