Scalable Atomic Arrays for Spin-Based Quantum Computers in Silicon

Semiconductor spin qubits combine excellent quantum performance with the prospect of manufacturing quantum devices using industry-standard metal-oxide-semiconductor (MOS) processes. This applies also to ion-implanted donor spins, which further afford exceptional coherence times and large Hilbert space dimension in their nuclear spin. Here we demonstrate and integrate multiple strategies to manufacture scale-up donor-based quantum computers. We use ${}^{31}$PF${}_2$ molecule implants to triple the placement certainty compared to ${}^{31}$P ions, while attaining 99.99$$% confidence in detecting the implant. Similar confidence is retained by implanting heavier atoms such as ${}^{123}$Sb and ${}^{209}$Bi, which represent high-dimensional qudits for quantum information processing, while Sb${}_2$ molecules enable deterministic formation of closely-spaced qudits. We demonstrate the deterministic formation of regular arrays of donor atoms with 300$$nm spacing, using step-and-repeat implantation through a nano aperture. These methods cover the full gamut of technological requirements for the construction of donor-based quantum computers in silicon.