Interplay between topological protected valley and quantum Hall edge transport

Abstract

An established way of realizing topologically protected states in a two-dimensional electron gas is by applying a perpendicular magnetic field thus creating quantum Hall edge channels. In electrostatically gapped bilayer graphene intriguingly, even in the absence of a magnetic field topologically protected electronic states can emerge at naturally occurring stacking domain walls. While individually both types of topologically protected states have been investigated, their intriguing interplay remains poorly understood. Here, we focus on the interplay between topological domain wall states and quantum Hall edge transport within the eight-fold degenerate zeroth Landau level of high-quality suspended bilayer graphene. We find that the two-terminal conductance remains approximately constant for low magnetic fields throughout the distinct quantum Hall states since the conduction channels are traded between domain wall and device edges. For high magnetic fields, however, we observe evidence of transport suppression at the domain wall, which can be attributed to the emergence of spectral minigaps. This indicates that stacking domain walls do potentially do not correspond to a topological domain wall in the order parameter.

References in corpus (15)

• Quantum Hall Ferromagnetism in Graphene
• Topological confinement in bilayer graphene
• Photonic crystals for nano-light in moiré graphene superlattices
• Quantum Anomalous Hall State in Bilayer Graphene
• Electronic Highways in Bilayer Graphene
• Evidence for a Spin Phase Transition at ν=0 in Bilayer Graphene
• Minimum Conductivity and Evidence for Phase Transitions in Ultra-clean Bilayer Graphene
• Tunable quantum anomalous Hall octet driven by orbital magnetism in bilayer graphene
• Conformal Invariance and Shape-Dependent Conductance of Graphene Samples
• Edge excitations of the canted antiferromagnetic phase of the $\nu =0$ quantum Hall state in graphene: a simplified analysis
• Transport Gap in Suspended Bilayer Graphene at Zero Magnetic Field
• Transconductance fluctuations as a probe for interaction induced quantum Hall states in graphene
• Spin Symmetry of the Bilayer Graphene Groundstate
• Distinct Competing Ordered ν=2 States in Bilayer Graphene
• Dual-gated graphene devices for near-field nano-imaging

Cited by in corpus (4)

• One-dimensional proximity superconductivity in the quantum Hall regime
• Quantum Valley and Sub-valley Hall Effect in the Large Angle Twisted Bilayer Graphene
• Energy symmetry and interlayer wave function ratio of tunneling electrons in partially overlapped graphene
• Large positive magnetoconductance in carbon nanoscrolls