Residual exchange interaction in linear spin qubit arrays

In the NISQ era quantum computation requires short gate times due to limited coherence times of qubits and optimal control parameters to perform high fidelity gates and readout. In spin qubit devices the exchange interaction between spins enables two-qubit gates and is often regulated by a middle barrier gate voltage. However to turn off exchange interaction the voltage has to be tuned rather high on short time scales and leaves the issue of residual exchange in qubit devices of several kHz. The fidelity of quantum gates is limited in the presence of residual exchange interaction. Therefore, we investigate the time evolution of single-qubit and two-qubit gates with residual exchange. In particular we look at the gate fidelity and the error operation that is left after a gate is applied and how to reduce this effect.