  Quantum dot-based quantum computation employs extensively the exchange
interaction between nearby electronic spins in order to manipulate and couple
different qubits. The exchange interaction, however, couples the qubit states
to charge noise, which reduces the fidelity of the quantum gates that employ
it. The effect of charge noise can be mitigated by working at noise sweetspots
in which the sensitivity to charge variations is reduced. In this work we study
the response to charge noise of a double quantum dot based qubit in the
presence of ac gates, with arbitrary driving amplitudes, applied either to the
dot levels or to the tunneling barrier. Tuning with an ac driving allows to
manipulate the sign and strength of the exchange interaction as well as its
coupling to environmental electric noise. Moreover, we show the possibility of
inducing a second-order sweetspot in the resonant spin-triplet qubit in which
the dephasing time is significantly increased.
