Please use this identifier to cite or link to this item: https://hdl.handle.net/10356/162589
Title: Tunable and giant valley-selective Hall effect in gapped bilayer graphene
Authors: Yin, Jianbo
Tan, Cheng
Barcons-Ruiz, David
Torre, Iacopo
Watanabe, Kenji
Taniguchi, Takashi
Song, Justin Chien Wen
Hone, James
Koppens, Frank H. L.
Keywords: Science::Physics
Issue Date: 2022
Source: Yin, J., Tan, C., Barcons-Ruiz, D., Torre, I., Watanabe, K., Taniguchi, T., Song, J. C. W., Hone, J. & Koppens, F. H. L. (2022). Tunable and giant valley-selective Hall effect in gapped bilayer graphene. Science, 375(6587), 1398-1402. https://dx.doi.org/10.1126/science.abl4266
Project: MOE2018-T3-1-002 
Journal: Science
Abstract: Berry curvature is analogous to magnetic field but in momentum space and is commonly present in materials with nontrivial quantum geometry. It endows Bloch electrons with transverse anomalous velocities to produce Hall-like currents even in the absence of a magnetic field. We report the direct observation of in situ tunable valley-selective Hall effect (VSHE), where inversion symmetry, and thus the geometric phase of electrons, is controllable by an out-of-plane electric field. We use high-quality bilayer graphene with an intrinsic and tunable bandgap, illuminated by circularly polarized midinfrared light, and confirm that the observed Hall voltage arises from an optically induced valley population. Compared with molybdenum disulfide (MoS2), we find orders of magnitude larger VSHE, attributed to the inverse scaling of the Berry curvature with bandgap. By monitoring the valley-selective Hall conductivity, we study the Berry curvature's evolution with bandgap. This in situ manipulation of VSHE paves the way for topological and quantum geometric optoelectronic devices, such as more robust switches and detectors.
URI: https://hdl.handle.net/10356/162589
ISSN: 0036-8075
DOI: 10.1126/science.abl4266
Rights: © 2022 American Association for the Advancement of Science. All rights reserved.
Fulltext Permission: none
Fulltext Availability: No Fulltext
Appears in Collections:SPMS Journal Articles

SCOPUSTM   
Citations 50

2
Updated on Nov 22, 2022

Web of ScienceTM
Citations 50

1
Updated on Nov 22, 2022

Page view(s)

13
Updated on Nov 29, 2022

Google ScholarTM

Check

Altmetric


Plumx

Items in DR-NTU are protected by copyright, with all rights reserved, unless otherwise indicated.