题目/Title：A Polar-Modulation-Based Cryogenic Transmon Qubit State Controller in 28 nm Bulk CMOS for Superconducting Quantum Computing

作者/Author：
                        Yanshu Guo, Qichun Liu, Yaoyu Li, Wenqiang Huang, Tian Tian, Siqi Zhang, Nan Wu, Songyao Tan, Ning Deng, Zhihua Wang, Hanjun Jiang, Tiefu Li, Yuanjin Zheng

期刊/Journal：IEEE Journal of Solid-State Circuits

年份/Issue Date：2023Sept.

卷（期）及页码/Volume（No.）&pages：Vol.58, No.11, pp.3060-3073

This article presents a cryogenic transmon qubit state controller integrated circuit (IC) working at a temperature of 3.5 K for superconducting quantum computing (QC) applications. The qubit state controller IC comprises a polar-modulation-based XY -path driver and a current-steering digital-to-analog converter (DAC)-based  ${Z}$ -path driver. To generate the XY -path driving pulse with arbitrary envelopes in the frequency range of 4–6 GHz, a switched-capacitor digital power amplifier (DPA) is adopted for amplitude modulation, and an injection locking local oscillator (IL-LO) with a constant-slope digital-to-time-converter (DTC) is used for open-loop phase modulation. With the proposed DPA and IL-LO, the controller can control a qubit with a compact architecture. Fabricated in the 28-nm bulk CMOS process, the controller IC occupies an active die area of 0.9 mm2 per driving channel. The controller achieves a spurious-free dynamic range (SFDR) of 40 dB for a 1 GS/s XY -path driver and an SFDR of 48 dB for a 1 GS/s  ${Z}$ -path driver at 3.5 K. The controller consumes a power of 13.7 mW per qubit. A Rabi experiment at 13.9 MHz, a Ramsey experiment at 3.09 MHz, and a T1 experiment at 15.87  $\mu \text{s}$  are conducted using the presented controller IC at 3.5 K to control the transmon superconducting qubit at 10 mK directly.