Quantum measurement of a mesoscopic spin ensemble
G. Giedke, Jacob M. Taylor, Domenica D’Alessandro +2 more
We describe a method for precise estimation of the polarization of a mesoscopic spin ensemble by using its coupling to a single two-level system. Our approach requires a minimal number of measurements on the two-level system for a given measurement precision. We consider the application of this method to the case of nuclear-spin ensemble defined by a single electron-charged quantum dot: we show that decreasing the electron spin dephasing due to nuclei and increasing the fidelity of nuclear-spin-based quantum memory could be within the reach of present day experiments.
arXiv:quant-ph/0508144•Physical Review A•Sep 15, 2006•87 citations