Deconfined fractional electric charges in graphene at high magnetic fields

TL;DR

This paper suggests that high magnetic fields induce a Kekule instability in graphene, leading to deconfined fractional electric charges, supported by resistance divergence and disorder effects.

Contribution

It demonstrates that magnetic fields induce a Kekule instability in graphene, enabling deconfined fractional charges, a novel phenomenon in condensed matter physics.

Findings

Resistance at Dirac point diverges under strong magnetic fields.

Magnetic field induces Kekule instability in graphene.

Disorder allows separation of fractional charges.

Abstract

The resistance at the charge neutral (Dirac) point was shown by Checkelsky et al in Phys. Rev. B 79, 115434 (2009) to diverge upon the application of a strong magnetic field normal to graphene. We argue that this divergence is the signature for a Kekule instability of graphene, which is induced by the magnetic field. We show that the strong magnetic field does not remove the zero modes that bind a fraction of the electron around vortices in the Kekule dimerization pattern, and that quenched disorder present in the system makes it energetically possible to separate the fractional charges. These findings, altogether, indicate that graphene can sustain deconfined fractionalized electrons.