193 research outputs found
Quasi-adiabatic Switching for Metal-Island Quantum-dot Cellular Automata
Recent experiments have demonstrated a working cell suitable for implementing
the Quantum-dot Cellular Automata (QCA) paradigm. These experiments have been
performed using metal island clusters. The most promising approach to QCA
operation involves quasi-adiabatically switching the cells. This has been
analyzed extensively in gated semiconductor cells. Here we present a metal
island cell structure that makes quasi-adiabatic switching possible. We show
how this permits quasi-adiabatic clocking, and enables a pipelined
architecture.Comment: 40 preprint-style double-spaced pages including 16 figure
FiktĂv vallomĂĄs Ă©s szövegmƱködĂ©s. Dosztojevszkij: ,Ărdögökâ
A vallomĂĄsos elbeszĂ©lĂ©s kĂŒlönös vilĂĄgossĂĄggal mutat rĂĄ a nyelvi mƱködĂ©s ama sajĂĄtossĂĄgĂĄra, hogy nem vonhatĂł Ă©les hatĂĄr a reprezentĂĄciĂłs (leĂrĂł, megjelenĂtĆ) nyelvi funkciĂł Ă©s a fikciĂłteremtĆ potencialitĂĄs között
Entanglement Detection in the Stabilizer Formalism
We investigate how stabilizer theory can be used for constructing sufficient
conditions for entanglement. First, we show how entanglement witnesses can be
derived for a given state, provided some stabilizing operators of the state are
known. These witnesses require only a small effort for an experimental
implementation and are robust against noise. Second, we demonstrate that also
nonlinear criteria based on uncertainty relations can be derived from
stabilizing operators. These criteria can sometimes improve the witnesses by
adding nonlinear correction terms. All our criteria detect states close to
Greenberger-Horne-Zeilinger states, cluster and graph states. We show that
similar ideas can be used to derive entanglement conditions for states which do
not fit the stabilizer formalism, such as the three-qubit W state. We also
discuss connections between the witnesses and some Bell inequalities.Comment: 15 pages including 2 figures, revtex4; typos corrected, presentation
improved; to appear in PR
Cluster mean-field study of the parity conserving phase transition
The phase transition of the even offspringed branching and annihilating
random walk is studied by N-cluster mean-field approximations on
one-dimensional lattices. By allowing to reach zero branching rate a phase
transition can be seen for any N <= 12.The coherent anomaly extrapolations
applied for the series of approximations results in and
.Comment: 6 pages, 5 figures, 1 table included, Minor changes, scheduled for
pubication in PR
Number operator-annihilation operator uncertainty as an alternative of the number-phase uncertainty relation
We consider a number operator-annihilation operator uncertainty as a well
behaved alternative to the number-phase uncertainty relation, and examine its
properties. We find a formulation in which the bound on the product of
uncertainties depends on the expectation value of the particle number. Thus,
while the bound is not a constant, it is a quantity that can easily be
controlled in many systems. The uncertainty relation is approximately saturated
by number-phase intelligent states. This allows us to define amplitude
squeezing, connecting coherent states to Fock states, without a reference to a
phase operator. We propose several setups for an experimental verification.Comment: 8 pages including 3 figures, revtex4; v2: typos corrected,
presentation improved; v3: presentation considerably extended; v4: published
versio
The Place of Äechovâs Dramas in Peter Szondiâs Theory of Drama
The paper examines Peter Szondiâs theory of drama from two perspectives: 1. what traces of his new approach â i.e. textual interpretation â can be found in his early works; 2. to what extent are Szondiâs conclusions valid and original with respect to Äechovâs dramatic works? I identify common characteristics of Szondiâs conception of literature, formalist poetics, and phenomenological approaches. I also analyse two features of modern drama, epicization and the role of the intimate Self, through interpretations of Äechovâs dramas. I come to the conclusion that monologues acquire a narrative function in Äechovâs works, while through inner speech they also preserve the linguistic compactness characteristic of lyric poetry, i.e. the sound effects (alliteration, assonance and richly metaphorical language), which generates meaning-producing processes in the dramatic text
A mƱfajfogalom ĂșjraĂ©rtĂ©sĂ©nek esĂ©lyei az eurĂłpai irodalmi hagyomĂĄnyban : SzĂĄvai Dorottya Ă©s Z. Varga ZoltĂĄn, szerk. MƱfaj Ă©s komparatisztika. Budapest: Gondolat KiadĂł, 2017, 493 lap
Two-setting Bell Inequalities for Graph States
We present Bell inequalities for graph states with high violation of local
realism. In particular, we show that there is a two-setting Bell inequality for
every nontrivial graph state which is violated by the state at least by a
factor of two. These inequalities are facets of the convex polytope containing
the many-body correlations consistent with local hidden variable models. We
first present a method which assigns a Bell inequality for each graph vertex.
Then for some families of graph states composite Bell inequalities can be
constructed with a violation of local realism increasing exponentially with the
number of qubits. We also suggest a systematic way for obtaining Bell
inequalities with a high violation of local realism for arbitrary graphs.Comment: 8 pages including 2 figures, revtex4; minor change
Rare regions of the susceptible-infected-susceptible model on BarabĂĄsi-Albert networks
I extend a previous work to susceptible-infected-susceptible (SIS) models on weighted BarabĂĄsi-Albert scale-free networks. Numerical evidence is provided that phases with slow, power-law dynamics emerge as the consequence of quenched disorder and tree topologies studied previously with the contact process. I compare simulation results with spectral analysis of the networks and show that the quenched mean-field (QMF) approximation provides a reliable, relatively fast method to explore activity clustering. This suggests that QMF can be used for describing rare-region effects due to network inhomogeneities. Finite-size study of the QMF shows the expected disappearance of the epidemic threshold λc in the thermodynamic limit and an inverse participation ratio âŒ0.25, meaning localization in case of disassortative weight scheme. Contrarily, for the multiplicative weights and the unweighted trees, this value vanishes in the thermodynamic limit, suggesting only weak rare-region effects in agreement with the dynamical simulations. Strong corrections to the mean-field behavior in case of disassortative weights explains the concave shape of the order parameter Ï(λ) at the transition point. Application of this method to other models may reveal interesting rare-region effects, Griffiths phases as the consequence of quenched topological heterogeneities
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