论文标题
使用多门体系结构从原子上精确的石墨烯纳米容器中调谐量子点
Tunable quantum dots from atomically precise graphene nanoribbons using a multi-gate architecture
论文作者
论文摘要
原子上精确的石墨烯纳米纤维(GNR)越来越引起人们的兴趣,因为它们在很大程度上可修改了电子性能,可以通过控制其化学合成过程中的宽度和边缘结构来量身定制。近年来,对电子设备的GNR特性的开发集中在GNR集成中,将其集成到现场效应 - 透射器(FET)几何形状中。但是,由于存在单栅极,因此此类FET设备的静电可调性有限。在这里,我们将9个宽扶手椅石墨烯纳米纤维(9-AGNR)的设备整合到一个多门FET几何形状中,该几何形状由超鼻手指的栅极和两个侧门组成。我们使用高分辨率电子束光刻(EBL)来定义狭窄至12 nm的手指门,并将它们与石墨烯电极混合在一起,以接触GNR。低温传输光谱测量结果揭示了具有丰富的库仑钻石模式的量子点(QD)行为,这表明GNRS形成QD,它们均以串联和并行连接。此外,我们表明,附加门可以使QD在纳米结中对QD进行差异调整,从而为基于GNR的多点系统的多门控制提供了第一步。
Atomically precise graphene nanoribbons (GNRs) are increasingly attracting interest due to their largely modifiable electronic properties, which can be tailored by controlling their width and edge structure during chemical synthesis. In recent years, the exploitation of GNR properties for electronic devices has focused on GNR integration into field-effect-transistor (FET) geometries. However, such FET devices have limited electrostatic tunability due to the presence of a single gate. Here, we report on the device integration of 9-atom wide armchair graphene nanoribbons (9-AGNRs) into a multi-gate FET geometry, consisting of an ultra-narrow finger gate and two side gates. We use high-resolution electron-beam lithography (EBL) for defining finger gates as narrow as 12 nm and combine them with graphene electrodes for contacting the GNRs. Low-temperature transport spectroscopy measurements reveal quantum dot (QD) behavior with rich Coulomb diamond patterns, suggesting that the GNRs form QDs that are connected both in series and in parallel. Moreover, we show that the additional gates enable differential tuning of the QDs in the nanojunction, providing the first step towards multi-gate control of GNR-based multi-dot systems.