  Recent achievements in the field of gate defined semiconductor quantum dots
reinforce the concept of a spin-based quantum computer consisting of nodes of
locally connected qubits which communicate with each other via superconducting
circuit resonator photons. In this work we theoretically demonstrate a
versatile set of quantum gates between adjacent spin qubits defined in
semiconductor quantum dots situated within the same node of such a spin-based
quantum computer. The electric dipole acquired by the spin of an electron that
moves across a double quantum dot potential in a magnetic field gradient has
enabled strong coupling to resonator photons and low-power spin control. Here
we show that this flopping-mode spin qubit also provides with the tunability to
program multiple two-qubit gates. Since the capacitive coupling between these
qubits brings about additional dephasing, we calculate the estimated infidelity
of different two-qubit gates in the most immediate possible experimental
realizations.
