Tenasini Giulia, Soler-Delgado David, Wang Zhe, Yao Fengrui, Dumcenco Dumitru, Giannini Enrico, Watanabe Kenji, Taniguchi Takashi, Moulsdale Christian, Garcia-Ruiz Aitor, Fal'ko Vladimir I, Gutiérrez-Lezama Ignacio, Morpurgo Alberto F
MOE Key Laboratory for Non-equilibrium Synthesis and Modulation of Condensed Matter, Shaanxi Province Key Laboratory of Advanced Materials and Mesoscopic Physics, School of Physics, Xi'an Jiaotong University, Xi'an 710049, China.
Research Center for Functional Materials, NIMS, 1-1 Namiki, Tsukuba 305-0044, Japan.
Nano Lett. 2022 Aug 24;22(16):6760-6766. doi: 10.1021/acs.nanolett.2c02369. Epub 2022 Aug 5.
We report experimental investigations of transport through bilayer graphene (BLG)/chromium trihalide (CrX; X = Cl, Br, I) van der Waals interfaces. In all cases, a large charge transfer from BLG to CrX takes place (reaching densities in excess of 10 cm), and generates an electric field perpendicular to the interface that opens a band gap in BLG. We determine the gap from the activation energy of the conductivity and find excellent agreement with the latest theory accounting for the contribution of the σ bands to the BLG dielectric susceptibility. We further show that for BLG/CrCl and BLG/CrBr the band gap can be extracted from the gate voltage dependence of the low-temperature conductivity, and use this finding to refine the gap dependence on the magnetic field. Our results allow a quantitative comparison of the electronic properties of BLG with theoretical predictions and indicate that electrons occupying the CrX conduction band are correlated.
我们报告了关于通过双层石墨烯（BLG）/三卤化铬（CrX；X = Cl、Br、I）范德华界面进行输运的实验研究。在所有情况下，都会发生从BLG到CrX的大量电荷转移（电荷密度超过10 cm），并产生垂直于界面的电场，该电场在BLG中打开一个带隙。我们从电导率的激活能确定带隙，并发现与考虑σ带对BLG介电常数贡献的最新理论非常吻合。我们进一步表明，对于BLG/CrCl和BLG/CrBr，带隙可以从低温电导率对栅极电压的依赖性中提取出来，并利用这一发现来完善带隙对磁场的依赖性。我们的结果允许将BLG的电子特性与理论预测进行定量比较，并表明占据CrX导带的电子是相关的。
