Gyakushi Takayuki, Amano Ikuma, Tsurumaki-Fukuchi Atsushi, Arita Masashi, Takahashi Yasuo
Graduate School of Information Science and Technology, Hokkaido University, Sapporo, 060-0814, Japan.
Sci Rep. 2022 Jul 6;12(1):11446. doi: 10.1038/s41598-022-15734-1.
Multidot single-electron devices (SEDs) can enable new types of computing technologies, such as those that are reconfigurable and reservoir-computing. A self-assembled metal nanodot array film that is attached to multiple gates is a candidate for use in such SEDs for achieving high functionality. However, the single-electron properties of such a film have not yet been investigated in conjunction with optimally controlled multiple gates because of the structural complexity of incorporating many nanodots. In this study, Fe nanodot-array-based double-gate SEDs were fabricated by vacuum deposition, and their single-electron properties (modulated by the top- and bottom-gate voltages; V and V, respectively) were investigated. The phase of the Coulomb blockade oscillation systematically shifted with V, indicating that the charge state of the single dot was controlled by both the gate voltages despite the metallic random multidot structure. This result demonstrates that the Coulomb blockade oscillation (originating from the dot in the multidot array) can be modulated by the two gates. The top and bottom gates affected the electronic state of the dot unevenly owing to the geometrical effect caused by the following: (1) vertically asymmetric dot shape and (2) variation of the dot size (including the surrounding dots). This is a characteristic feature of a nanodot array that uses self-assembled metal dots; for example, prepared by vacuum deposition. Such variations derived from a randomly distributed nanodot array will be useful in enhancing the functionality of multidot devices.
多点单电子器件（SED）能够实现新型计算技术，比如可重构计算技术和储层计算技术。附着于多个栅极的自组装金属纳米点阵列薄膜是用于此类高功能SED的候选材料。然而，由于纳入许多纳米点的结构复杂性，尚未结合最佳控制的多个栅极来研究这种薄膜的单电子特性。在本研究中，通过真空沉积制备了基于铁纳米点阵列的双栅SED，并研究了其单电子特性（分别由顶栅电压和底栅电压(V_t)和(V_b)调制）。库仑阻塞振荡的相位随(V_b)系统性地移动，这表明尽管存在金属随机多点结构，但单量子点的电荷状态受两个栅极电压的控制。该结果表明，（源自多点阵列中的量子点的）库仑阻塞振荡可由两个栅极调制。由于以下几何效应，顶栅和底栅对量子点电子态的影响不均衡：（1）垂直不对称的量子点形状和（2）量子点尺寸的变化（包括周围的量子点）。这是使用自组装金属量子点的纳米点阵列的一个特征；例如，通过真空沉积制备。源自随机分布的纳米点阵列的此类变化将有助于增强多点器件的功能。
