Chen Guorui, Zhang Ya-Hui, Sharpe Aaron, Zhang Zuocheng, Wang Shaoxin, Jiang Lili, Lyu Bosai, Li Hongyuan, Watanabe Kenji, Taniguchi Takashi, Shi Zhiwen, Goldhaber-Gordon David, Zhang Yuanbo, Wang Feng
Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education), Shenyang National Laboratory for Materials Science, School of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240, China.
Department of Physics, University of California at Berkeley, Berkeley, California 94720, United States.
Nano Lett. 2023 Aug 9;23(15):7023-7028. doi: 10.1021/acs.nanolett.3c01741. Epub 2023 Jul 20.
ABC-stacked trilayer graphene on boron nitride (ABC-TLG/hBN) moiré superlattices provides a tunable platform for exploring Wigner crystal states in which the electron correlation can be controlled by electric and magnetic fields. Here we report the observation of magnetic field-stabilized Wigner crystal states in a ABC-TLG/hBN. We show that correlated insulating states emerge at multiple fractional and integer fillings corresponding to ν = /, /, 1, /, /, and 2 electrons per moiré lattice site under a magnetic field. These correlated insulating states can be attributed to generalized Mott states for the integer fillings and generalized Wigner crystal states for the fractional fillings. The generalized Wigner crystal states are stabilized by a vertical magnetic field and are strongest at one magnetic flux quantum per three moiré superlattices. The ν = 2 insulating state persists up to 30 T, which can be described by a Mott-Hofstadter transition at a high magnetic field.
氮化硼上的ABC堆叠三层石墨烯（ABC-TLG/hBN）莫尔超晶格为探索维格纳晶体态提供了一个可调谐平台，其中电子关联可通过电场和磁场进行控制。在此，我们报告了在ABC-TLG/hBN中观察到磁场稳定的维格纳晶体态。我们表明，在磁场下，对应于每个莫尔晶格位点ν = 1/3、1/2、1、2/3、3/4和2个电子的多个分数和整数填充处出现了关联绝缘态。这些关联绝缘态可归因于整数填充时的广义莫特态和分数填充时的广义维格纳晶体态。广义维格纳晶体态由垂直磁场稳定，并且在每三个莫尔超晶格一个磁通量量子时最强。ν = 2绝缘态在高达30 T时仍然存在，这可以用高磁场下的莫特 - 霍夫施塔特转变来描述。
