Eight-Qubit Operation of a 300 mm SiMOS Foundry-Fabricated Device
Authors
Andreas Nickl
Nard Dumoulin Stuyck
Paul Steinacker
Jesus D. Cifuentes
Santiago Serrano
MengKe Feng
Ensar Vahapoglu
Fay E. Hudson
Kok Wai Chan
Stefan Kubicek
Julien Jussot
Yann Canvel
Sofie Beyne
Yosuke Shimura
Roger Loo
Clement Godfrin
Bart Raes
Sylvain Baudot
Danny Wan
Arne Laucht
Chih-Hwan Yang
Wee Han Lim
Andre Saraiva
Christopher C. Escott
Kristiaan De Greve
Andrew S. Dzurak
Tuomo Tanttu
Abstract
Silicon spin qubits are a promising candidate for quantum computing, thanks to their high coherence, high controllability and manufacturability. However, the most scalable complementary metal-oxide-semiconductor (CMOS) based implementations have so far been limited to a few qubits. Here, to take a step towards large scale systems, we tune and coherently control an eight-dot linear array of silicon spin qubits fabricated in 300 mm CMOS-compatible foundry process, establishing operational scalability beyond the two-qubit regime. All eight qubits are successfully tuned and characterized as four double dot pairs, exhibiting Ramsey dephasing times $T_2^*$ up to 41(2) $μ$s and Hahn-echo coherence times $T_2^{\mathrm{Hahn}}$ up to 1.31(4) ms. Readout of the central four qubits is achieved via a cascaded charge-sensing protocol, enabling simultaneous high-fidelity measurements of the entire multi-qubit array. Additionally, we demonstrate a two-qubit gate operation between adjacent qubits with low phase noise. We demonstrate here that we can scale silicon spin qubit arrays to medium-sized arrays of 8 qubits while maintaining coherence of the system.
