Development of simultaneous detection method of millimeter-wave ESR and EDMR signals of phosphorous-doped silicon

We report the development of a measurement system enabling simultaneous detection of millimeter-wave electron spin resonance (ESR) and electrically detected magnetic resonance (EDMR) signals in lightly phosphorus-doped silicon (Si:P). Such simultaneous detection is motivated by the need to clarify spin-dependent transport and dynamic nuclear polarization mechanisms in high magnetic-field and low-temperature conditions relevant to Si:P-based quantum computing architectures. A Si:P sample was mounted on a Fabry-Pérot resonator and was equipped with comb-shaped electrodes optimized for millimeter-wave transmission, allowing ESR excitation while monitoring the resistance changes under optical illumination. Using a 130 GHz millimeter-wave source, we successfully observed ESR absorption signals and corresponding EDMR responses simultaneously at temperatures around 5 K. The EDMR signals exhibited sharper linewidths compared to ESR. These results demonstrate the feasibility of combined ESR–EDMR measurements and provide a foundation for future studies on coupled electron–nuclear spin dynamics, including the simultaneous observation of ESR and EDMR.