Abstract
Single electron devices have been researched and developed in nano-electronics for the past ten years. Due to the behavior of transferring electrons one by one, the single electron transistor (SET) and the single electron pump were also gazed at in metrology. A new silicon-based single electron pump with SET-island-SET configuration was developed in our laboratory. Two feature of this pump should be noted. The first one is that electrons are transferred one by one during pump operation. For pump operation, two AC signals of 90∘phase difference with the same amplitude and frequency are added to the DC gate voltages of the two SETs. Drain-source voltage is set at 0 V, and the operation temperature is 10 K. The potential energies of the three islands (including two islands of the SETs and the central island) are varied by the two sine waves of 90∘phase difference. Electrons can be transferred through the device due to the variation of potential energies in the islands. Produced pump current IP is dependent on the frequency f of the sine waves: IP = ef. The quantized current is formed as electrons are transferred one by one. The number of transferred electrons per cycle is controlled by increasing the amplitude of the AC signals. The second feature of this device is the polarity of the pump current can be switched. Choosing different DC gate voltages of the two SETs or changing phase difference between two AC signals, the direction of the pump current is changed. Therefore, a new sort of Si-based single electron pump, which has both abilities for transporting electrons one by one and switching polarity of the pump current without varying drain-source voltage, was fabricated and developed. The behavior of this new device is well explained by the energy diagram of SET-island-SET configuration.