Periodic Coulomb blockade oscillations observed in single-layered Fe nanodot array

Double-Gate Operation of Metal Nanodot-Array-Based Single-Electron Device

“…These contour maps are simple and periodic, as indicated by the yellow dotted lines, although there is an irregularity in Fig. 3b at V T = 17 V, which is caused by charge noise that may be attributed to the effect of satellite nanodots acting as the single-electron traps 37 . These characteristics can con rm that the major current oscillation certainly originates from a single dot 37 .…”

“…In both devices, the current oscillations were added to the constant background current components (~520 pA (Device A) and ~1.0 nA (Device B)), which were attributed to the parallel conductive paths comprising the dots with the Coulomb blockade lifted. Such dots attributing to the background current are considered relatively large and/or have higher tunneling conductance than the quantized value (2e 2 /h) 37 . By comparing the I D -V B curves with different V T values, a systematic shift in the current peak was identi ed.…”

“…3b at V T = 17 V, which is caused by charge noise that may be attributed to the effect of satellite nanodots acting as the single-electron traps 37 . These characteristics can con rm that the major current oscillation certainly originates from a single dot 37 . Controllability of the charge state of the single dot by the double-gate is clearly con rmed despite the multidot structure.…”

“…Finally, the gate-insulating SiO 2 (300 nm) layer was prepared on the MgF 2 layer via sputtering, followed by the top-gate electrode (Au/Cr) formation. Details of the device fabrication are given in a previous study 37 . The drain current between the source and drain electrodes (I D ) was measured using a semiconductor parameter analyzer (Agilent 4156C) by applying the voltages V T and V B to the Au/Cr top-gate and Si (substrate) back-gate electrodes, respectively, in a closed-cycle cryogenic probe station at the sample stage temperature T of 8 K.…”

“…In these cases, the array comprises randomly distributed nanodots and numerous conduction paths with different properties must be formed. Although the single-electron tunneling properties may be di cult to detect in such complex systems, the Coulomb blockade properties were frequently detected [29][30][31][32][33][34][35][36][37][38] and the modulation caused by the gate voltage was clear and simple in some cases 32,35,37,38 . To determine the potential of these complex-array SEDs, further investigations using multigate operation are required.…”