Santa Barbara, Calif. A discovery by physicists at UC Santa Barbara may earn silicon carbide a semiconductor commonly used by the electronics industry a role at the center of a new generation of information technologies designed to exploit quantum physics for tasks such as ultrafast computing and nanoscale sensing.
The research team discovered that silicon carbide contains crystal imperfections that can be controlled at a quantum mechanical level. The finding is published this week in the journal Nature.
The research group of David Awschalom, senior author, made the finding. Awschalom is director of UCSB's Center for Spintronics & Quantum Computation, professor of physics, electrical and computer engineering, and the Peter J. Clarke Director of the California NanoSystems Institute.
In conventional semiconductor-based electronic devices, crystal defects are often deemed undesirable because of their tendency to immobilize electrons by "trapping" them at a particular crystal location. However, the UCSB team discovered that electrons that become trapped by certain imperfections in silicon carbide do so in a way that allows their quantum states to be initialized, precisely manipulated, and measured using a combination of light and microwave radiation. This means that each of these defects meets the requirements for use as a quantum bit, or "qubit," which is often described as the quantum mechanical analog of a transistor, since it is the basic unit of a quantum computer.
"We are looking for the beauty and utility in imperfection, rather than struggling to bring about perfect order," said Awschalom, "and to use these defects as the basis for a future quantum technology."
Most crystal imperfections do not possess these properties, which are intimately tied to the atomic structure of a defect and the electronic characteristics of its semiconductor host, explained Awschalom. In fact, before this research, the on
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University of California - Santa Barbara