Introduction

Fault-tolerant quantum computing requires high-fidelity qubits.

We speed up the spin rotation by utilizing a micromagnet and realized high-fidelity qubits even in industry-standard natural silicon.

Experiment

The left picture shows a scanning electron micrograph of the device. A double quantum dot is formed at the position of the small blue circles. We can detect the charge state by monitoring a quantum dot sensor indicated by a large blue circle.

We apply microwaves to induce the electron spin resonance. The microwave electric field and the magnetic field created by the micromagnet induce the rotation of the spin.