Quantum control of spin qubits using SOT-driven nanomagnets

Abstract

Spin rotation (SR) is an essential capability for realization of single and two-qubit gates in spin quantum computing (SQC) architectures. To perform SR, resonant AC magnetic fields are either generated by microwave current pulses fed to an antenna, or voltage pulses applied to a gate, in presence of an inhomogeneous Zeeman field. While the former approach is limited by gate-speed and site-selectivity of SR, the latter adds to the decoherence of the spin qubits. Here, we propose an alternative technique for driving high-speed SR without compromising the qubit coherence, by employing spin-orbit-torque (SOT)-driven nanomagnets to produce oscillating magnetic fields, locally at the qubit site. The proposed scheme is highly energy-efficient, scalable, and compatible with the CMOS fabrication technology.