  Scaling up spin qubit systems requires high-fidelity single-qubit and
two-qubit gates. Gate fidelities exceeding $98\%$ were already demonstrated in
silicon based single and double quantum dots, whereas for the realization of
larger qubit arrays crosstalk effects on neighboring qubits must be taken into
account. We analyze qubit fidelities impacted by crosstalk when performing
single-qubit and two-qubit operations on neighbor qubits with a simple
Heisenberg model. Furthermore we propose conditions for driving fields to
robustly synchronize Rabi oscillations and avoid crosstalk effects. In our
analysis we also consider next to nearest neighbor crosstalk and show that
double synchronization leads to a restricted choice for the driving field
strength, exchange interaction, and thus gate time. Considering realistic
experimental conditions we propose a set of parameter values to perform a
nearly crosstalk-free CNOT gate and so open up the pathway to scalable quantum
computing devices.
