H. Nakashima et K. Uozumi, Zero-bias transfer of single electrons in a turnstile device designed withtrapezoidal tunneling barriers, PHYS REV B, 59(11), 1999, pp. 7312-7315
The transfer of single electrons has been theoretically studied in a turnst
ile device with four identical tunnel junctions of capacitance C and a gate
capacitor of capacitance C/2, designed with identical asymmetric tunneling
barriers instead of symmetric tunneling barriers. The zero-current offset
in the current-voltage characteristic of this turnstile is not at zero-bias
voltage when the amplitude of an applied ac gate voltage is greater than e
/C; that is, electrons can be transferred through the device with an applie
d ac gate signal but without bias voltage. This unusual transfer characteri
stic is due to a rectification nature of electron tunneling in asymmetric t
unneling barriers. [S0163-1829(99)10811-7].