Abstract
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
T
and
V
B
, respectively) were investigated. The phase of the Coulomb blockade oscillation systematically shifted with
V
T
, 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.
Abstract Multi-dot single-electron devices (SEDs) have been fabricated using very thin Fe films by vacuum deposition on thermally oxidized or sputter-deposited SiO 2 substrates. Although the SEDs ...fabricated on the two substrates showed very different conductance, Coulomb blockade (CB) oscillation clearly appeared in certain Fe thickness ranges for both cases. The CB oscillation changed from complex to simple with increasing Fe thickness, indicating that the decrease of the number of dots contributed to the CB oscillation. While the simple CB monotonically disappeared by the drain voltage ( V D ), the complex CB was robust against V D because V D distributed over the array composed of plural dots. The CB property change from complex to simple appeared in different thickness ranges for the two substrates, but in similar conductance ranges. This demonstrates that the conductance influenced by the inter-dot distance is an important factor for the CB characteristics of randomly distributed multi-dot SEDs.
Multi-dot single-electron devices (SEDs) can expect to have high functionality by attaching many input/output terminals. In this paper, Fe nanodot-array-based multi-dot SEDs were fabricated and their ...single-electron properties were studied. We clarified that although the size of the devices is on the micrometer-scale, clear Coulomb blockade oscillations are observed as a function of the gate voltage. Such large-size devices are relatively easy to be attached by multiple input/output terminals. Therefore, the result suggests that the Fe-nanodot devices can be expected to have a potential to achieve high functionality such as flexible-logic-gate operation.
Single-electron devices (SEDs) composed of nanometer-scale dots have been attracted due to their low-power consumption and high functionality. In this paper, we fabricated double-gate SEDs formed by ...Fe nanodot array which showed periodic Coulomb blockade oscillation characteristics derived from a single dot. As a result, we confirmed that the charge state of the single dot could be controlled by two gates. In addition, we also found an interesting phenomenon that the two gates, which attached parallel to the nanodot array, unevenly affected the nanodots.
