Process Tomography of a nuclear quadrupolar spin quantum processor : Characterization of quantum algorithms and non-Markovian decoherence
In the present work the first virtual 2 Qubit solid state NMR quantum processor, using a spin- 3/2 Na quadrupolar nucleus in a NaNO3 single crystal, is presented. Methods from liquid NMR quantum information processing, like strongly modulating pulses, are adopted to the quadrupolar spin system to implement the unitary operations and to generate pseudo pure states. Experimentally a set of quantum algorithms as well as the decoherence process is characterized by quantum process tomography which is developed for the quadrupolar spin system. A detailed analyses of the basic conditions of the experimental quantum process tomography procedure is presented, showing that even in such non-Markovian systems this method is valid.