Spin-qubit control with a milli-kelvin CMOS chip
Published in Nature
Samuel K. Bartee, Will Gilbert, Kun Zuo, Kushal Das, Tuomo Tanttu, Chih Hwan Yang, Nard Dumoulin Stuyck, Sebastian J. Pauka, Rocky Y. Su, Wee Han Lim, Santiago Serrano, Christopher C. Escott, Fay E. Hudson, Kohei M. Itoh, Arne Laucht, Andrew S. Dzurak & David J. Reilly
Abstract
A key virtue of spin qubits is their sub-micron footprint, enabling a single silicon chip to host the millions of qubits required to execute useful quantum algorithms with error correction. However, with each physical qubit needing multiple control lines, a fundamental barrier to scale is the extreme density of connections that bridge quantum devices to their external control and readout hardware. A promising solution is to co-locate the control system proximal to the qubit platform at milli-kelvin temperatures, wired up by miniaturized interconnects. Even so, heat and crosstalk from closely integrated control have the potential to degrade qubit performance, particularly for two-qubit entangling gates based on exchange coupling that are sensitive to electrical noise. Here we benchmark silicon metal-oxide-semiconductor (MOS)-style electron spin qubits controlled by heterogeneously integrated cryo-complementary metal-oxide-semiconductor (cryo-CMOS) circuits with a power density sufficiently low to enable scale-up. Demonstrating that cryo-CMOS can efficiently perform universal logic operations for spin qubits, we go on to show that milli-kelvin control has little impact on the performance of single- and two-qubit gates. Given the complexity of our sub-kelvin CMOS platform, with about 100,000 transistors, these results open the prospect of scalable control based on the tight packaging of spin qubits with a ‘chiplet-style’ control architecture.
