A 5.5mW/Channel 2-to-7 GHz Frequency Synthesizable Qubit-Controlling Cryogenic Pulse Modulator for Scalable Quantum Computers

This work presents a qubit controller IC based on the direct synthesis. The IC consists of six independently-working pulse modulators utilizing the same LO frequency. We propose a sinusoid-shaping nonlinear DAC followed by a linear interpolating DAC to improve both of energy and hardware efficiencies. The implemented IC in 40nm CMOS is verified by superconducting qubit operations with Rabi and Ramsey oscillations while consuming power of < 1/60 compared with the previous state-of-the-art.