Unconventional Correlation between Quantum Hall Transport Quantization and Bulk State Filling in Gated Graphene Devices.
We report simultaneous transport and scanning microwave impedance microscopy to examine the correlation between transport quantization and filling of the bulk Landau levels in the quantum Hall regime in gated graphene devices. Surprisingly, a comparison of these measurements reveals that quantized transport typically occurs below the complete filling of bulk Landau levels, when the bulk is still conductive. This result points to a revised understanding of transport quantization when carriers are accumulated by gating. We discuss the implications on transport study of the quantum Hall effect in graphene and related topological states in other two-dimensional electron systems.
Geballe Laboratory for Advanced Materials (GLAM), Stanford University, Stanford, California 94305, USA.
Yong-Tao
YT
Cui
Department of Physics, Columbia University, New York, New York 10027, USA.
Bo
B
Wen
Geballe Laboratory for Advanced Materials (GLAM), Stanford University, Stanford, California 94305, USA.
Eric Y
EY
Ma
Geballe Laboratory for Advanced Materials (GLAM), Stanford University, Stanford, California 94305, USA.
Georgi
G
Diankov
Department of Physics, Columbia University, New York, New York 10027, USA.
Zheng
Z
Han
Department of Physics and Astronomy, Appalachian State University, Boone, North Carolina 28607, USA.
Francois
F
Amet
National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan.
Takashi
T
Taniguchi
National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan.
Kenji
K
Watanabe
Geballe Laboratory for Advanced Materials (GLAM), Stanford University, Stanford, California 94305, USA.
David
D
Goldhaber-Gordon
Department of Physics, Columbia University, New York, New York 10027, USA.
Cory R
CR
Dean
Geballe Laboratory for Advanced Materials (GLAM), Stanford University, Stanford, California 94305, USA.
Zhi-Xun
ZX
Shen