A surface acoustic wave has enabled scientists at the University of Cambridge to gain greater control over how electrons move from one place to another.
A team in the Cavendish Laboratory was able to move an individual electron along a wire, batting it back and forth more than 60 times, like a game of ping-pong. For the research project, a single electron is trapped in a small well or quantum dot, just inside the surface of a piece of gallium arsenide. A channel leads to another empty dot four microns away, and is higher in energy than the surrounding electrons. A short burst of sound is then sent along the surface past the dot, and the accompanying wave of electrical potential picks up the electron, which then surfs along the channel to the other dot where it is captured. A sound burst sent from the other direction returns the electron to the starting dot where the process can be repeated.
"Although our experiments do not yet show that electrons 'remember' their quantum state, this is likely to be the case," says Cambridge's Chris Ford. "This would make the method of transfer a candidate for moving quantum bits of information [qubits] around a quantum circuit, in a quantum computer."
From University of Cambridge
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