  A proposal for a phase gate and a M{\o}lmer-S{\o}rensen (MS) gate in the
dressed state basis is presented. In order to perform the multi-qubit
interaction, a strong magnetic field gradient is required to couple the
phonon-bus to the qubit states. The gate is performed using resonant microwave
driving fields together with either a radio-frequency (RF) driving field, or
additional detuned microwave driving fields. The gate is robust to ambient
magnetic field fluctuations due to an applied resonant microwave driving field.
Furthermore, the gate is robust to fluctuations in the microwave Rabi frequency
and is decoupled from phonon dephasing due to a resonant RF or a detuned
microwave driving field. This makes this new gate an attractive candidate for
the implementation of high-fidelity microwave based multi-qubit gates. The
proposal can also be realized in laser-based set-ups.
