Design Considerations for Spin Readout Amplifiers in Monolithically Integrated Semiconductor Quantum Processors

The high frequency performance of all active and passive devices in a production 22nm FDSOI CMOS technology was measured up to 40 GHz over temperature down to 3.3 Kelvin, targeting applications in cryogenic and quantum computing ICs. It was found that the quality factor of the passives and the fT and fMAX of both p- and n-MOSFETs improved at 3.3 K. More importantly for circuit design, the peakfT and peak-fMAX current densities, and the MOM capacitor and polysilicon resistor values show no variance with temperature. This information and the measured I-V characteristics of electron and hole single- and double-quantum dot structures, measured at 2 K and representative of qubits, were used to design monolithically integrated double quantum dots with readout transimpedance amplifiers output matched to 50 Ω. Transimpedance gain, S21, and bandwidth of 108 dBΩ, 19 dB, and 7.5 GHz, respectively, were measured at 300 K with only 4.5 mW power consumption and S22 < -10 dB up to 60 GHz.