Abstract
Using standard microfabrication techniques, it is now possible to construct devices that appear to reliably manipulate electrons one at a time. These devices have potential use as building blocks in quantum computing devices, or as a standard of electrical current derived only from a frequency and the fundamental charge. To date, the error rate in semiconductor ‘tuneable-barrier’ pump devices, those which show most promise for high-frequency operation, have not been tested in detail. We present high-accuracy measurements of the current from an etched GaAs quantum dot pump, operated at zero source–drain bias voltage with a single ac-modulated gate at 340 MHz driving the pump cycle. By comparison with a reference current derived from primary standards, we show that the electron transfer accuracy is better than 15 parts per million. High-resolution studies of the dependence of the pump current on the quantum dot tuning parameters also reveal possible deviations from a model used to describe the pumping cycle.
Highlights
Using standard microfabrication techniques, it is possible to construct devices that appear to reliably manipulate electrons one at a time
Unlike the multiple-junction pumps, the hybrid turnstile needs only one ac control signal, and the current can be increased by operating many devices in parallel [9]
The hybrid turnstile needs to be operated at finite bias voltage ≈ 1 mV, and eliminating the errors due to leakage currents is a challenging ongoing project [10]
Summary
This content has been downloaded from IOPscience. Please scroll down to see the full text. 2010 New J. Download details: IP Address: 144.82.107.91 This content was downloaded on 02/12/2013 at 14:55 Please note that terms and conditions apply
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