Donor Spins in Silicon for Quantum Technologies

Abstract

Dopant atoms are ubiquitous in semiconductor technologies, providing the tailored electronic properties that underpin the modern digital information era. Harnessing the quantum nature of these atomic‐scale objects represents a new and exciting technological revolution. In this article, the use of ion‐implanted donor spins in silicon for quantum technologies is described. It is reviewed how to fabricate and operate single‐atom spin qubits in silicon, obtaining some of the most coherent solid‐state qubits, and pathways to scale up these qubits to build large quantum processors are discussed. Heavier group‐V donors with large nuclear spins display electric quadrupole couplings that enable nuclear electric resonance, quantum chaos, and strain sensing. Donor ensembles can be coupled to microwave cavities to develop hybrid quantum Turing machines. Counted, deterministic implantation of single donors, combined with novel methods for precision placement, will allow the integration of individual donor spins with industry‐standard silicon fabrication processes, making implanted donors a prime physical platform for the second quantum revolution.

Long-range spin jump diffusion revealed by dynamic light scattering

“…Donor electron spins in semiconductors are being actively studied as they hold great promise in the context of quantum technologies [1][2][3]. Such spins are among the most coherent quantum systems in the solid state and can be efficiently exploited by using advanced semiconductor technology [4,5]. Long-distance displacement of individual electron spins is another key ingredient for scalability in a spin-based semiconductor quantum circuit.…”

Advances and opportunities in materials science for scalable quantum computing

“…sources of noise and decoherence associated with amorphous materials, particularly in superconducting circuit devices, are reviewed in Müller et al; 37 these defects also are responsible for important effects in silicon-based devices, ion traps, and possibly other technologies. The fabrication, design, characterization, and operation of donor spins in silicon are reviewed in Morello et al 38 Optical quantum computing technologies are not covered in this issue, since major materials science challenges and advances are still emerging in that field.…”

On the VCO/Frequency Divider Interface in Cryogenic CMOS PLL for Quantum Computing Applications

“…Several qubit realizations are presented in the literature where the logical states |0> and |1> are encoded in single-electron spin in a quantum dot, singlet-triplet spin states in double quantum dot, three electrons spin states in triple quantum dot, or an all-electrical realization of quantum dot qubit, where three electrons are confined in a double quantum dot, called hybrid qubit [7]. Analogous qubit realizations are achieved for the donor scenario [8].…”