Anomalous single-electron transfer in common-gate quadruple-dot single-electron devices with asymmetric junction capacitances

• Published in: Japanese Journal of Applied Physics 2018-06, Vol.57 (6), p.64001
• Main Authors: Imai, Shigeru, Ito, Masato
• Format: Article
• Language: English
• Subjects: Electric potential; Electrodes; Electron transfer; Electron tunneling; Electrons; Islands
• ISSN: 0021-4922; 1347-4065
• DOI: 10.7567/JJAP.57.064001

In this paper, anomalous single-electron transfer in common-gate quadruple-dot turnstile devices with asymmetric junction capacitances is revealed. That is, the islands have the same total number of excess electrons at high and low gate voltages of the swing that transfers a single electron. In another situation, two electrons enter the islands from the source and two electrons leave the islands for the source and drain during a gate voltage swing cycle. First, stability diagrams of the turnstile devices are presented. Then, sequences of single-electron tunneling events by gate voltage swings are investigated, which demonstrate the above-mentioned anomalous single-electron transfer between the source and the drain. The anomalous single-electron transfer can be understood by regarding the four islands as "three virtual islands and a virtual source or drain electrode of a virtual triple-dot device . The anomalous behaviors of the four islands are explained by the normal behavior of the virtual islands transferring a single electron and the behavior of the virtual electrode.