Chromium defects in silicon carbide may provide a new platform for quantum information.

Quantum computers may be able to solve scientific problems that are impossible for today’s fastest conventional supercomputers. Quantum sensors can measure signals that cannot be measured by today’s most sensitive sensors. Quantum bits are the building blocks of these devices.

Scientists are investigating various quantum systems and exploring applications for quantum computers. One system, the spin qubit, is based on controlling the orientation of an electron’s spin at the sites of defects in semiconductor materials that make up the qubit.

Defects may include small amounts of material different from the main material from which the semiconductor is made. Researchers recently demonstrated how to make high-quality spin qubits based on chromium defects in silicon carbide.

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Researchers investigate chromium defects in silicon carbide as potential spin qubits. One advantage of these spin qubits is that they emit light at wavelengths compatible with telecommunications optical fibers. This means they are potentially useful for quantum networks that use fibers to interconnect fibers. Unfortunately, material quality issues have limited the feasibility of these spin qubits.

Researchers have recently discovered new ways to create chromium defects in silicon carbide. He implanted chromium ions into silicon carbide and then heated them to 1600 °C. This resulted in a material with spin defects, which has a very high quality. This result could lead to quantum communication using current semiconductor and fiber optic technologies.

Observation
An increasing number of attempts to commercialize quantum computers and quantum sensors have led to heavy investments in specific types of qubits. However, researchers have to overcome many challenges to realize practical quantum computing, communication and sensing.

First, they require a better understanding of the fundamental limits of the different types of qubits. Spin qubits are particularly interesting because electronic spin can store information for a longer time than many other types of qubits.

Furthermore, these qubits can be used at room temperature and can be controlled and read using optics. Optical interfaces will be critical to the development of this technology, as photons can carry quantum information over large distances using existing telecommunications fiber networks.

The study reported here showed that chromium ions implanted in commercially available silicon carbide substrates and then annealed at high temperatures generate single spin defects that can be used for spin qubits. Is. The same method can be used to produce vanadium or molybdenum defects as researchers continue to search for the ideal orbit.

References: Burke Diller, Samuel J. Whiteley, Christopher P. Anderson, Gary Wolfowicz, Mary E. Wesson, Edward S. Belzec, F. “Coherent Control and High-Fidelity Readout of Chromium Ions in Commercial Silicon Carbide” by Joseph Herremann. and David D.

The project was supported by the Department of Energy’s (DOE) Office of Science, Basic Energy Science, Materials Science and Engineering Division. This work was done in part by the Center for Integrated Nanotechnologies, a DOE Office of Science User Facility.