Curator's Take
This comprehensive review arrives at a crucial juncture for spin qubits, which are increasingly viewed as the dark horse candidate for large-scale quantum computing due to their impressive coherence times and natural compatibility with existing semiconductor fabrication processes. The paper's focus on long-range coupling mechanisms is particularly timely, as connecting distant spin qubits remains one of the biggest engineering challenges preventing these systems from scaling beyond small proof-of-concept devices. What makes this work especially valuable is its coverage of cutting-edge approaches like topological spin textures and hybrid circuit QED architectures, which could provide the missing link between spin qubits' excellent local properties and the connectivity requirements for fault-tolerant quantum computers. For anyone tracking the hardware race in quantum computing, this review offers essential context for understanding why major players like Intel and SiQure are betting heavily on silicon spin platforms.
— Mark Eatherly
Summary
Spin qubits have emerged as a leading platform for quantum information processing due to their long coherence times, small footprint, and compatibility with the existing semiconductor industry. We first provide an introduction to the different qubit implementations currently being investigated, including single electron-spin qubits, hole-spin qubits, donor qubits, and multispin encodings. We discuss how the confinement and strain present in semiconductor heterostructures produce addressable levels whose spin degree of freedom can be used to encode a qubit. A large emphasis is placed on reviewing the theoretical foundations and recent experimental demonstrations of proposed mechanisms for long-range coupling, including hybrid approaches based on circuit QED and Andreev qubits, as well as spin shuttling. Finally, we review a recent proposal for linking spin qubits using topological spin textures.