SPICE Workshop on Quantum Functionalities of Nanomagnets, June 17th - 19th 2025
Monica Benito
The ability for optically active media to rotate the polarization of light is the basis of polarimetry, an illustrious technique responsible for many breakthroughs in fields as varied as astronomy, medicine and material science. Here [1], we recast the primary mechanism for spin readout in semiconductor-based quantum computers, Pauli spin-blockade (PSB), as the natural extension of polarimetry to the third dimension. We perform polarimetry with spins through a silicon quantum dot exchanging a hole with a boron acceptor, demonstrating the role of spin-orbit coupling in creating spin misalignment. Perfect spin alignment may be recovered by means of rotating the applied magnetic-field orientation. This work [1] shows how spin misalignment sets a fundamental upper limit for the spin readout fidelity in quantum-computing systems based on PSB.
To avoid this limitation, a tunable spin-orbit coupling is desirable. I will present our latest theoretical proposal on how to employ magnetic skyrmions to tune the spin-orbit coupling of Si electron spin qubits.
[1] Peri, L., von Horstig, F. E., Barraud, S., Ford, C. J., Benito, M., & Gonzalez-Zalba, M. F. Polarimetry With Spins in the Solid State. arXiv:2410.17867.