Valley-momentum locking in a graphene superlattice with Y-shaped Kekulé bond texture

Recent experiments by Gutiérrez et al (2016 Nat. Phys. 12 950) on a graphene-copper superlattice have revealed an unusual Kekulé bond texture in the honeycomb lattice-a Y-shaped modulation of weak and strong bonds with a wave vector connecting two Dirac points. We show that this so-called 'Kek-...

Full description

Saved in:
Bibliographic Details
Published inNew journal of physics Vol. 20; no. 2; pp. 23016 - 23026
Main Authors Gamayun, O V, Ostroukh, V P, Gnezdilov, N V, Adagideli, Beenakker, C W J
Format Journal Article
LanguageEnglish
Published Bristol IOP Publishing 07.02.2018
Subjects
Bonding strength
Fermions
Graphene
Kekule distortion
Locking
massless Dirac fermions
Momentum
Physics
Superlattices
Texture
valley-momentum locking
Online AccessGet full text

Cover

More Information
Summary:Recent experiments by Gutiérrez et al (2016 Nat. Phys. 12 950) on a graphene-copper superlattice have revealed an unusual Kekulé bond texture in the honeycomb lattice-a Y-shaped modulation of weak and strong bonds with a wave vector connecting two Dirac points. We show that this so-called 'Kek-Y' texture produces two species of massless Dirac fermions, with valley isospin locked parallel or antiparallel to the direction of motion. In a magnetic field B, the valley degeneracy of the B-dependent Landau levels is removed by the valley-momentum locking but a B-independent and valley-degenerate zero-mode remains.
Bibliography:NJP-107705.R1
ISSN:1367-2630
1367-2630
DOI:10.1088/1367-2630/aaa7e5