  We present a scheme for full quantum state tomography tailored for two spin
qubits in a double quantum dot. A set of 15 quantum states allows to determine
the density matrix in this two-qubit space by projective measurement. In this
paper we choose a set gained from mutually unbiased bases. We determine how
those 15 projections can be represented by charge measurements after a
spin-to-charge conversion and the application of quantum gates. The quantum
gates include exchange-based gates as well as rotations by electron spin
resonance (ESR). We assume the experimental realization of ESR operations to be
more difficult than the exchange gate operation. Therefore, it is an important
result that the ESR gates are limited by a pi/2 rotation for one of the
electron spins per measurement.
