State-conditional coherent charge qubit oscillations in a Si/SiGe quadruple quantum dot

摘要

Researchers in the United States and Korea demonstrate control of individual electrons in an electronic device governed by quantum mechanics. Mark Eriksson from the University of Wisconsin-Madison and co-workers developed a building block for a quantum computer that traps single electrons between nanoscale-spaced electrical contacts on silicon–germanium. Instead of using electrical signals to create the ones and zeros used in traditional information processing, quantum computers use physical objects called quantum bits, or qubits. The qubit used by Eriksson's team is known as a quantum dot charge qubit. The team created two pairs of quantum dots and used the position of an electron in one pair to influence quantum oscillations of the electron in the other pair. Coupling double quantum dots in this way could form the basis of a compact quantum-computing architecture that is compatible with the fabrication techniques used in modern electronics.