Researchers demonstrate high-frequency charge detection in 2D quantum devices

Researchers at Tohoku University and Japan's National Institute for Materials Science demonstrated sensitive, high-frequency charge detection in quantum devices made from two-dimensional materials. The technique addresses high electrical resistance that has hindered fast measurements of these devices. The team integrated a variable capacitor made from strontium titanate into a high-frequency resonant circuit. This matched the circuit's electrical impedance to the devices closely enough to detect individual electrons entering and leaving a quantum dot. The system remained stable under a perpendicular magnetic field, a required operating condition for spin-valley qubits. The demonstrated capability concerns charge detection, which supports the repetitive measurements needed to develop these quantum devices.