Nonlinear Response and Crosstalk of Electrically Driven Silicon Spin Qubits

Frequency multiplexing of operations is an attractive strategy to control multiple qubits simultaneously in a spin-based quantum processor with relatively few control lines. However, high-fidelity operation demands good spectral addressability and noncontextual spin dynamics. The authors explore an unexpected crosstalk mechanism, in which the Rabi frequency of one spin changes markedly depending on the simultaneous operation of another. They also connect this behavior to another surprising feature: the nonlinear scaling of Rabi frequency with resonant driving amplitude. These results provide insight into the challenges that such state-of-the-art control methods will face.