129
views
0
recommends
+1 Recommend
0 collections
    0
    shares
      • Record: found
      • Abstract: found
      • Article: found
      Is Open Access

      Quantum Computation with Quantum Dots

      Preprint
      ,

      Read this article at

      Bookmark
          There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

          Abstract

          We propose a new implementation of a universal set of one- and two-qubit gates for quantum computation using the spin states of coupled single-electron quantum dots. Desired operations are effected by the gating of the tunneling barrier between neighboring dots. Several measures of the gate quality are computed within a newly derived spin master equation incorporating decoherence caused by a prototypical magnetic environment. Dot-array experiments which would provide an initial demonstration of the desired non-equilibrium spin dynamics are proposed.

          Related collections

          Most cited references4

          • Record: found
          • Abstract: found
          • Article: found
          Is Open Access

          Measurement of conditional phase shifts for quantum logic

          , , (2009)
          Measurements of the birefringence of a single atom strongly coupled to a high-finesse optical resonator are reported, with nonlinear phase shifts observed for intracavity photon number much less than one. A proposal to utilize the measured conditional phase shifts for implementing quantum logic via a quantum-phase gate (QPG) is considered. Within the context of a simple model for the field transformation, the parameters of the "truth table" for the QPG are determined.
            Bookmark
            • Record: found
            • Abstract: found
            • Article: found
            Is Open Access

            Complete Characterization of a Quantum Process: the Two-Bit Quantum Gate

            We show how to fully characterize a quantum process in an open quantum system. We particularize the procedure to the case of a universal two-qubit gate in a quantum computer. We illustrate the method with a numerical simulation of a quantum gate in the ion trap quantum computer.
              Bookmark
              • Record: found
              • Abstract: found
              • Article: found
              Is Open Access

              Quantum Computers, Factoring, and Decoherence

              , , (2009)
              In a quantum computer any superposition of inputs evolves unitarily into the corresponding superposition of outputs. It has been recently demonstrated that such computers can dramatically speed up the task of finding factors of large numbers -- a problem of great practical significance because of its cryptographic applications. Instead of the nearly exponential (\(\sim \exp L^{1/3}\), for a number with \(L\) digits) time required by the fastest classical algorithm, the quantum algorithm gives factors in a time polynomial in \(L\) (\(\sim L^2\)). This enormous speed-up is possible in principle because quantum computation can simultaneously follow all of the paths corresponding to the distinct classical inputs, obtaining the solution as a result of coherent quantum interference between the alternatives. Hence, a quantum computer is sophisticated interference device, and it is essential for its quantum state to remain coherent in the course of the operation. In this report we investigate the effect of decoherence on the quantum factorization algorithm and establish an upper bound on a ``quantum factorizable'' \(L\) based on the decoherence suffered per operational step.
                Bookmark

                Author and article information

                Journal
                08 January 1997
                1997-07-20
                Article
                10.1103/PhysRevA.57.120
                cond-mat/9701055
                975623db-9d62-444f-9433-1fc77be85776
                History
                Custom metadata
                Phys. Rev. A 57, 120 (1998)
                12 pages, Latex, 2 ps figures. v2: 20 pages (very minor corrections, substantial expansion), submitted to Phys. Rev. A
                cond-mat.mes-hall quant-ph

                Quantum physics & Field theory,Nanophysics
                Quantum physics & Field theory, Nanophysics

                Comments

                Comment on this article