Dynamical symmetry breaking, magnetization and induced charge in graphene: Interplay between magnetic and pseudomagnetic fields

Abstract

In this paper, we investigate the two competing effects of strains and magnetic fields in single-layer graphene with the aim to explore its impact in various phenomena of quantum field theory, such as induced charge density, magnetic catalysis, symmetry breaking, dynamical mass generation, and magnetization. We show that real and strain-induced pseudomagnetic fields are the catalysts of dynamical chiral, time-reversal and parity symmetry breaking, where the last two symmetry breakings are related to the dynamical generation of a Haldane mass term. We find that it is possible to modify, by straining and varying the external magnetic field, the magnetization and the dynamical mass independently for each valley. Furthermore, we discover that the presence of a non-zero pseudomagnetic field, unlike the magnetic field, allows us to observe an induced "vacuum" charge, as well as a parity anomaly in strained graphene. Finally, because the combined effect of real and pseudomagnetic fields produces an induced valley polarization, the results presented here may provide new tools to design valleytronic devices.