A Heat-Resilient Spin Qubit in Silicon

Thermal effects have recently emerged as a key limitation for scalable spin-based quantum processors. Local heating from microwave control pulses can shift qubit Larmor frequencies, degrading gate fidelities. Here, we investigate these thermal effects in a single hole spin confined in a silicon quantum dot. By measuring the Larmor frequency as a function of temperature and magnetic field orientation, we reveal a strong thermal susceptibility up to tens of MHz/K. Our analysis demonstrates that this effect originates from spin-orbit-induced electrical susceptibility, and numerical simulations point to thermally activated electric dipoles that modify the local electrostatic field as the microscopic origin. Remarkably, the hole spin thermal susceptibility depends on the magnetic field orientation, and we unveil the existence of “sweet spots” where the Larmor frequency becomes temperature-independent. These results provide a microscopic understanding of spin thermal susceptibility and establish design principles for heat-resilient qubit operation in silicon.