Cheng Shen^1,2, Yanbang Chu^1,2, QuanSheng Wu^3,4*, Na Li^1,2, Shuopei Wang^1,5, Yanchong Zhao^1,2, Jian Tang^1,2, Jieying Liu^1,2, Jinpeng Tian^1,2, Kenji Watanabe⁶, Takashi Taniguchi⁶, Rong Yang^1,7,5, Zi Yang Meng^1,8,5, Dongxia Shi^1,2,7, Oleg V. Yazyev^3,4*, Guangyu Zhang^1,2,5,7*

1 Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing, China

2 School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, China

3 Institute of Physics, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland

4 National Centre for Computational Design and Discovery of Novel Materials (MARVEL), Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland

5 Songshan Lake Materials Laboratory, Dongguan, Guangdong, China

6 National Institute for Materials Science, 1-1 Namiki, Tsukuba, Japan

7 Beijing Key Laboratory for Nanomaterials and Nanodevices, Beijing, China

8 HKU-UCAS Joint Institute of Theoretical and Computational Physics, Department of Physics, The University of Hong Kong, Hong Kong, China

* Corresponding authors emails: quansheng.wu@epfl.ch, oleg.yazyev@epfl.ch, gyzhang@iphy.ac.cn

DOI10.24435/materialscloud:be-eq [version v1]

Publication date: Jan 09, 2021

How to cite this record

Cheng Shen, Yanbang Chu, QuanSheng Wu, Na Li, Shuopei Wang, Yanchong Zhao, Jian Tang, Jieying Liu, Jinpeng Tian, Kenji Watanabe, Takashi Taniguchi, Rong Yang, Zi Yang Meng, Dongxia Shi, Oleg V. Yazyev, Guangyu Zhang, Correlated states in twisted double bilayer graphene, Materials Cloud Archive 2021.4 (2021), https://doi.org/10.24435/materialscloud:be-eq

Description

Electron–electron interactions play an important role in graphene and related systems and can induce exotic quantum states, especially in a stacked bilayer with a small twist angle. For bilayer graphene where the two layers are twisted by the ‘magic angle’, flat band and strong many-body effects lead to correlated insulating states and superconductivity. In contrast to monolayer graphene, the band structure of untwisted bilayer graphene can be further tuned by a displacement field, providing an extra degree of freedom to control the flat band that should appear when two bilayers are stacked on top of each other. Here, we report the discovery and characterization of displacement field-tunable electronic phases in twisted double bilayer graphene. We observe insulating states at a half-filled conduction band in an intermediate range of displacement fields. Furthermore, the resistance gap in the correlated insulator increases with respect to the in-plane magnetic fields and we find that the g factor, according to the spin Zeeman effect, is ~2, indicating spin polarization at half-filling. These results establish twisted double bilayer graphene as an easily tunable platform for exploring quantum many-body states.

Materials Cloud sections using this data

Files

File name	Size	Description
TDBG_1.3degree_archive.tar.gz MD5md5:1394164cb9a2a900c011fc0cd89443f8	16.3 MiB	Input files for WannierTools necessary to reproduce the band structure plots in the reference.
README.txt MD5md5:f84aa10fd91a58f744a3667cb5368bf6	1016 Bytes	README file

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Keywords

twisted double bilayer graphene TDBG correlated states MARVEL CSCS EPFL