  Micromagnet-based electric dipole spin resonance (EDSR) offers an attractive
path for the near-term scaling of dense arrays of silicon spin qubits in
gate-defined quantum dots while maintaining long coherence times and high
control fidelities. However, accurately controlling dense arrays of qubits
using a multiplexed drive will require an understanding of the crosstalk
mechanisms that may reduce operational fidelity. We identify a novel crosstalk
mechanism whereby the Rabi frequency of a driven qubit is drastically changed
when the drive of an adjacent qubit is turned on. These observations raise
important considerations for scaling single-qubit control.
