Solid state qubit quantum state tomography - art. no. 69030D

Solid state quantum computer hardware may be based on rare-earth-ion-doped crystals. The qubits can be encoded as nuclear spin states of an ensemble of, e.g., Pr3+ ions, randomly doped into a Y2SiO5 crystal. Two such qubits can control each other through the dipole blockade effect, and transfers between the two qubit states can be done at a high fidelity, despite the strongly inhomogeneous nature of the ensemble approach. In this paper full control over the qubit Bloch sphere is demonstrated, by performing arbitrary qubit rotations and characterizing the outcomes using quantum state tomography.