Color Centers for Quantum Networking Devices


Quantum computing technology approaches wide application following research published on November 18 in Natural materials. An international collaboration, including Marina radulaski, an assistant professor in the Department of Electrical and Computer Engineering at UC Davis, showed how tiny defects in silicon carbide called color centers could be used to build quantum networking devices capable of translating signals between photons and electronic spin.

Quantum computing is based on the representation of information in the form of “Qubits” which can have values ​​of one or zero simultaneously. This could make possible computers much more powerful than conventional digital computers, at least for certain types of tasks. Currently, quantum computers are limited by the types of materials available to build and network them.

Radulaski and UC Davis graduate students Sridhar Majety and Pranta Saha collaborated with scientists in Germany, Japan and Sweden on the work. The project was led by Florian Kaiser from the University of Stuttgart.

Manufacture and electron microscopy of triangular silicon carbide waveguides. These devices exhibit useful properties for quantum networks.

Silicon Carbide Defects

“This project is part of our team’s research into triangular quantum photonics in silicon carbide,” Radulaski said. “One of our goals is to develop a quantum repeater, a key element in extending quantum communication over long distances. Our result shows that the optical and spin properties of silicon carbide color centers are preserved after integration into a triangular waveguide, which can efficiently guide emitted light through a single optical mode.

Color centers are defects in the structure of silicon carbide that allow photons to interact with the electronic spin properties of the material. Their integration with waveguides, devices that guide light, can be used to connect operations through a quantum processor.

Triangular devices are suitable for integrating color centers in an evolutionary way, necessary for the design of large-scale quantum systems, said Majety.

“Through this work, we have understood the limits of the positioning of the emitter inside triangular devices and shown that the defects can be integrated without significantly deteriorating their prospects for quantum applications,” he said.

The work was partly funded by a CAREER grant from NSF in Radulaski.