Transport in strained graphene: Interplay of Abelian and axial magnetic fields

Abstract

Immersed in external magnetic fields ($B$), buckled graphene constitutes an ideal tabletop setup, manifesting a confluence of time-reversal symmetry ($\mathcal{T}$) breaking Abelian ($B$) and $\mathcal{T}$-preserving strain-induced internal axial ($b$) magnetic fields. In such a system, here we numerically compute two-terminal conductance ($G$), and four- as well as six-terminal Hall conductivity (${\sigma }_{xy}$) for spinless fermions. On a flat graphene ($b=0$), the $B$ field produces quantized plateaus at $G=\pm |{\sigma }_{xy}|=(2n+1)e^2/h$, where $n=0,1,2,\cdots$. The strain induced $b$ field lifts the two-fold valley degeneracy of higher Landau levels and leads to the formation of additional even-integer plateaus at $G=\pm |{\sigma }_{xy}|=(2,4,\cdots )e^2/h$, when $B>b$. While the same sequence of plateaus is observed for $G$ when $b>B$, the numerical computation of ${\sigma }_{xy}$ in Hall bar geometries in this regime becomes unstable. A plateau at $G={\sigma }_{xy}=0$ always appears with the onset of a charge-density-wave order, causing a staggered pattern of fermionic density between two sublattices of the honeycomb lattice.

Published version in PRB: 7 pages, 4 figures: Supplemental Material as Ancillary file

References in corpus (8)

• Unconventional Integer Quantum Hall effect in graphene
• Interaction phenomena in graphene seen through quantum capacitance
• Excitonic gap, phase transition, and quantum Hall effect in graphene
• Theory of integer quantum Hall effect in graphene
• Strong-Magnetic-Field Magnon Transport in Monolayer Graphene
• Competing charge-density-wave, magnetic and topological ground states at and near Dirac points in graphene in axial magnetic fields
• Strained graphene Hall bar
• Analytic solution to pseudo-Landau levels in strongly bent graphene nanoribbons