in this paper, we present a simple method for preparation of graphene-zno nanocomposites (g-zno). the method is based on thermal treatment of the graphene oxide (go)/zno paste which reduces the graphene oxide into the graphene and leads to the formation of the g-zno nanocomposite. the structure, morphology and optical properties of synthesized nanocomposites are characterized with xrd, fesem, f...

We present a scheme for linear optical quantum computation that is highly robust to imperfect single photon sources and inefficient detectors. In particular we show that if the product of the detector efficiency with the source efficiency is greater than 2/3, then efficient linear optical quantum computation is possible. This high threshold is achieved within the cluster state paradigm for quan...

We introduce definitions of the quantum efficiency for binary-outcome qubit detectors with imperfect fidelity, focusing on the subclass of quantum nondemolition detectors. Quantum efficiency is analyzed for several models of detectors, including indirect projective measurement, linear detector in binary-outcome regime, detector of the superconducting phase qubit, and detector based on tunneling...

A number of optical technologies remain to be developed and optimized for various applications in quantum information processing, especially quantum communication. We will give an overview of our approach to some of these, including periodic heralded single-photon sources based on spontaneous parametric down-conversion, ultrabright sources of tunable entangled photons, near unit efficiency sing...