Electron-spin-resonance meanderlines for effective spin control in Si quantum dots for large-scale qubit applications

Coherent control of electron spins in multiple quantum dots (QDs) is critical for realizing large-scale spin qubits. The manipulation of electron spins in Si QDs can be achieved by electron spin resonance (ESR). While the effective spin control over a single qubit has been demonstrated, the architecture of ESR lines for large-scale spin qubits has yet to be demonstrated. In this paper, we propose an ESR meanderline for large-scale Si QDs. Simulation results show that magnetic fields can be effectively enhanced with low electric fields using a meanderline, enabling high-fidelity and low-noise control over electron spins in a 50-qubit system. Reflection coefficients of ESR meanderlines by on-wafer microwave measurements show low loss (-7 dB) for a 3-qubit device at a frequency range of 10 to 50 GHz.