Visualizing the Effect of an Electrostatic Gate with Angle-Resolved Photoemission Spectroscopy
Visualizing the Effect of an Electrostatic Gate with Angle-Resolved Photoemission Spectroscopy
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DOI：
10.1021/acs.nanolett.9b00649
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发表时间：
2019-04-01
期刊：
影响因子：
10.8
通讯作者：
Velasco, Jairo, Jr.
中科院分区：
文献类型：
--
作者：
Joucken, Frederic;Avila, Jose;Velasco, Jairo, Jr.
静电门控在材料科学中普遍存在，但其对材料电子能带结构的影响从未通过角分辨光电子能谱 (ARPES) 直接揭示，而角分辨光电子能谱 (ARPES) 是无创探测材料电子能带结构的首选技术。通过具有亚微米空间分辨率的最先进的 ARPES 装置，我们研究了由六方氮化硼上的伯纳尔堆叠双层石墨烯 (BLG) 组成并沉积在石墨片上的异质结构。通过对后者施加电压偏置，电场效应在 BLG 的价带以及碳核心层上直接可见。讨论了BLG在横向电场作用下的带隙张开情况，并提出了层内屏蔽的重要性。我们的结果为新研究铺平了道路，这些研究将使用动量分辨电子结构信息来深入了解受电场效应影响的材料的物理特性。
Electrostatic gating is pervasive in materials science, yet its effects on the electronic band structure of materials has never been revealed directly by angle-resolved photoemission spectroscopy (ARPES), the technique of choice to noninvasively probe the electronic band structure of a material. By means of a state-of-the-art ARPES setup with submicron spatial resolution, we have investigated a heterostructure composed of Bernal-stacked bilayer graphene (BLG) on hexagonal boron nitride and deposited on a graphite flake. By voltage biasing the latter, the electric field effect is directly visualized on the valence band as well as on the carbon is core level of BLG. The band gap opening of BLG submitted to a transverse electric field is discussed and the importance of intra layer screening is put forward. Our results pave the way for new studies that will use momentum-resolved electronic structure information to gain insight on the physics of materials submitted to the electric field effect.