IEEE Journal of Solid-State Circuits
A Polar-Modulation-Based Cryogenic Transmon Qubit State Controller in 28 nm Bulk CMOS for Superconducting Quantum Computing
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
Abstract
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.