Measurement of enhanced spin-orbit coupling strength for donor-bound electron spins in silicon

• Main Authors: Krishnan, Radha, Gan, Beng Yee, Hsueh, Yu-Ling, Huq, A. M. Saffat-Ee, Kenny, Jonathan, Rahman, Rajib, Koh, Teck Seng, Simmons, Michelle Y., Weber, Bent
• Other Authors: School of Physical and Mathematical Sciences
• Format: Article
• Language: English
• Published: 2025
• Subjects: Physics; Electric dipole spin resonance; Quantum dots
• Online Access: https://hdl.handle.net/10356/182314
• Institution: Nanyang Technological University

While traditionally considered a deleterious effect in quantum dot spin qubits, the spin-orbit interaction is recently being revisited as it allows for rapid coherent control by on-chip AC electric fields. For electrons in bulk silicon, spin-orbit coupling (SOC) is intrinsically weak, however, it can be enhanced at surfaces and interfaces, or through atomic placement. Here it is showed that the strength of the spin-orbit coupling can be locally enhanced by more than two orders of magnitude in the manybody wave functions of multi-donor quantum dots compared to a single donor, reaching strengths so far only reported for holes or two-donor system with certain symmetry. These findings may provide a pathway toward all-electrical control of donor-bound spins in silicon using electric dipole spin resonance (EDSR).