Technology Breakthrough: Duplex-Driven SiC Quantum Sensor Doubles Sensitivity at room temperature

A study conducted by Kosuke Tahara et al., in collaboration with the National Institutes for Quantum Science and Technology (QST), was published in npj Quantum Information.
This study addresses the long-standing problem of weak optical read-out from spin-3/2 silicon-vacancy centers (VSi) in silicon carbide (SiC)—an otherwise industry-friendly platform for chip-integrated quantum sensors. By simultaneously driving the two microwave transitions in the four-level manifold, it turns each defect into a pair of “duplex qubits,” recycling population that would otherwise generate background fluorescence. The dual-tone approach doubles photoluminescence contrast and halves the room-temperature AC-magnetometry detection limit, all with a simple laser-plus-two-MW setup, fully compatible with standard SiC fabrication. It demonstrates a promising proof of principle that could lead to future compact SiC-based quantum magnetometers for battery diagnostics, neural imaging, and structural-health monitoring.

This research was conducted under the Cabinet Office’s SIP program, “Promoting the Application of Advanced Quantum Technologies to Social Challenges” (Funding agency: QST).

Title: Quantum Sensing with Duplex Qubits of Silicon Vacancy Centers in SiC at Room Temperature
Authors: Tahara, K., Tamura, S., Toyama, H., Nakane, J., Kutsuki, K., Yamazaki, Y., Ohshima, T.
Journal Name: npj Quantum Information
Published: April 5, 2025
https://doi.org/10.1038/s41534-025-01011-2