Integer and fractional quantum anomalous Hall effects in pentalayer graphene

Abstract

We critically analyze the recently reported observation of integer (IQAHE) and fractional (FQAHE) quantum anomalous Hall effects at zero applied magnetic field in pentalayer graphene. Our quantitative activation and variable range hopping transport analysis of the experimental data reveals that the observed IQAHE and FQAHE at different fillings all have similar excitation gaps of the order of $5-10$ K. In addition, we also find that the observed FQAHE manifests a large hidden background contact series resistance >10 k$\Omega$ of unknown origin whereas this contact resistance is much smaller ~500 $\Omega$ in the observed IQAHE. Both of these findings are surprising as well as inconsistent with the well-established phenomenology of the corresponding high-field integer and fractional quantum Hall effects in 2D semiconductor systems.

Final published version

References in corpus (14)

• High temperature fractional quantum Hall states
• Fractional quantum Hall states at zero magnetic field
• Nearly-flat bands with nontrivial topology
• Observation of Fractionally Quantized Anomalous Hall Effect
• Fractional quantum Hall effect in the absence of Landau levels
• Flat bands and Wigner crystallization in the honeycomb optical lattice
• Observation of integer and fractional quantum anomalous Hall effects in twisted bilayer MoTe2
• Topological flat band models with arbitrary Chern numbers
• Spontaneous fractional Chern insulators in transition metal dichalcogenides Moire superlattices
• Crystalline gauge fields and quantized discrete geometric response for Abelian topological phases with lattice symmetry
• Fractional quantum Hall effect energy gap: role of electron layer thickness
• Quantum phases of disordered flatband lattice fractional quantum Hall systems
• On the zero-field quantization of the anomalous quantum Hall effect in moiré 2D layers
• Composite Fermion Mass

Cited by in corpus (9)

• Self-consistent theory for the fractional quantum anomalous Hall effect in rhombohedral pentalayer graphene
• Thermal crossover from a Chern insulator to a fractional Chern insulator in pentalayer graphene
• Fractional quantum anomalous Hall effect in rhombohedral multilayer graphene with a strong displacement field
• Quantum anomalous, spin, and valley Hall effects in pentalayer rhombohedral graphene moiré superlattices
• Edge-driven transition between extended quantum anomalous Hall crystal and fractional Chern insulator in rhombohedral graphene multilayers
• Multi-Band Exact Diagonalization and an Iteration Approach to Hunt For Fractional Chern Insulators in Rhombohedral Multilayer Graphene
• Chern-Selective multi-valley Flat Bands in Twisted Mono-Bilayer and Mono-Trilayer MoTe${}_2$
• Elastic Response and Instabilities of Anomalous Hall Crystals
• Time-dependent conserved operators for autonomous systems and quantization of resistance