Design of fully integrated 45 nm CMOS system-on-chip receiver for readout of transmon qubit

This study presents a comprehensive design approach focusing on quantum chip signal amplification by Josephson parametric amplifiers, and an integrated receiver for detecting ultra-low-level quantum signals. Quantum theory is used to analyze the dynamics of a transmon qubit coupled to a transmission line, entanglement between them, and design a parametric amplifier to amplify the quantum signals. Integration of these quantum devices with a 45 nm CMOS system-on-chip receiver creates a sophisticated blend of quantum and classical elements. The transmon qubit and parametric amplifier as a quantum chip, operating at 10 mK, are evaluated for key quantum metrics such as entanglement, Stoke projector probabilities, and parametric amplifier gain. Simultaneously, the resulting receiver combines high-performance components, including a low-noise amplifier with 0.76 dB noise figure in a broad bandwidth, a sweepable 5.0 GHz sinusoidal wave generator, and a purpose-designed mixer for C-band to zero-intermediate frequency (IF) conversion. An intermediate frequency amplifier with flat 26 dB gain and its low-pass filter property generates a pure sinusoidal wave at zero-IF, suitable for subsequent processing at room temperature. This design achieves a notable balance with low power consumption (~122 mW), a noise figure less than 0.9 dB, high gain (~65 dB), a wide bandwidth of 3.6 GHz, and compact dimensions (0.6 × 0.4 mm²). The fully integrated receiver, capable of reading out at least 90 qubits, positions this design for potential applications in quantum computing. Post-simulation validations at room temperature underscore the promising and innovative nature of this approach.