56,996 research outputs found
Localized quantum walks as secured quantum memory
We show that a quantum walk process can be used to construct and secure
quantum memory. More precisely, we show that a localized quantum walk with
temporal disorder can be engineered to store the information of a single,
unknown qubit on a compact position space and faithfully recover it on demand.
Since the localization occurss with a finite spread in position space, the
stored information of the qubit will be naturally secured from the simple
eavesdropper. Our protocol can be adopted to any quantum system for which
experimental control over quantum walk dynamics can be achieved.Comment: 7 pages, 4 figure
Invariant manifolds and the long-time asymptotics of the Navier-Stokes and vorticity equations on R^2
We construct finite-dimensional invariant manifolds in the phase space of the
Navier-Stokes equation on R^2 and show that these manifolds control the
long-time behavior of the solutions. This gives geometric insight into the
existing results on the asymptotics of such solutions and also allows one to
extend those results in a number of ways.Comment: 46 pages, 3 figure
Adaptive Predictive Control Using Neural Network for a Class of Pure-feedback Systems in Discrete-time
10.1109/TNN.2008.2000446IEEE Transactions on Neural Networks1991599-1614ITNN
Phases of random antiferromagnetic spin-1 chains
We formulate a real-space renormalization scheme that allows the study of the
effects of bond randomness in the Heisenberg antiferromagnetic spin-1 chain.
There are four types of bonds that appear during the renormalization flow. We
implement numerically the decimation procedure. We give a detailed study of the
probability distributions of all these bonds in the phases that occur when the
strength of the disorder is varied. Approximate flow equations are obtained in
the weak-disorder regime as well as in the strong disorder case where the
physics is that of the random singlet phase.Comment: 29 pages, 12 encapsulated Postscript figures, REVTeX 3.
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