We define what it means for a state in a convex cone of states on a space of observables to be generalized-entangled relative to a subspace of the observables, in a general ordered linear spaces framework for operational theories. This extends
the notion of ordinary entanglement in quantum information theory to a much more general framework. Some important special
cases are described, in which the distinguished observables are subspaces of the observables of a quantum system, leading
to results like the identification of generalized unentangled states with Lie-group-theoretic coherent states when the special
observables form an irreducibly represented Lie algebra. Some open problems, including that of generalizing the semigroup
of local operations with classical communication to the convex cones case, are discussed.
PACS: 03.65.Ud. 相似文献
A novel packet format with non-return-to-zero (NRZ) label and duobinary carrier-suppressed return-to-zero (DCS-RZ) payload is proposed for optical packet switching networks.NRZ label is followed by DCS-RZ payload with a certain guard time.The spectra of the low-rate NRZ label locate around the optical carrier frequency where some parts of the corresponding spectra of the high-rate DCS-RZ payload have been suppressed due to DCS-RZ modulation.At the switching node,the label or payload extraction can be realized simply through an optical bandpass or notch filter respectively.The feasibility of the scheme is verified by the simulation on the famous photonic design platform designed by Virtual Photonics Inc.(VPI).The effects of optical filter bandwidth on the received signal quality are discussed by analyzing bit error rate(BER)and contrast ratio performances. 相似文献
This article presents the realization of many self-reversible quantum logic gates using two-qubit quadrupolar spin 3/2 systems. Such operations are theoretically described using propagation matrices for the RF pulses that include the effect of the quadrupolar evolution during the pulses. Experimental demonstrations are performed using a generalized form of the recently developed method for quantum state tomography in spin 3/2 systems. By doing so, the possibility of controlling relative phases of superimposed pseudo-pure states is demonstrated. In addition, many aspects of the effect of the quadrupolar evolution, occurring during the RF pulses, on the quantum operations performance are discussed. Most of the procedures presented can be easily adapted to describe selective pulses of higher spin systems (>3/2) and for spin 1/2 under J couplings. 相似文献
Boneh and Venkatesan have recently proposed a polynomial time algorithm for recovering a ``hidden' element of a finite field of elements from rather short strings of the most significant bits of the remainder modulo of for several values of selected uniformly at random from . Unfortunately the applications to the computational security of most significant bits of private keys of some finite field exponentiation based cryptosystems given by Boneh and Venkatesan are not quite correct. For the Diffie-Hellman cryptosystem the result of Boneh and Venkatesan has been corrected and generalized in our recent paper. Here a similar analysis is given for the Shamir message passing scheme. The results depend on some bounds of exponential sums.
Stochastic resonance (SR) is based on the cooperative effect between
the stochastic dynamical system and the external forcing. As is well
known, the cooperative effect is produced by adding noises. In this
paper, we show the evidence that by changing the system parameters
and the signal intensity, a nonlinear system in the presence of an
input aperiodic signal can yield the cooperative effect, with the
noise fixed. To quantify the nonlinear system output, we determine
the theoretical bit error rate (BER). By numerical simulation, the
validity of the theoretical derivation is checked. Besides, we show
that parameter-induced SR is more realizable than SR via adding
noises, especially when the noise intensity exceeds the resonance
level, or when the characteristic of the noise is not known. 相似文献
In this paper we develop a new model for harvest operation costs that can be used to evaluate stands for potential harvest. The model is based on felling, extraction, and access costs and is unique in its consideration of the interaction between harvest area shapes and access roads. We illustrate the model and evaluate the impact of stand size, volume, and road cost when determining harvest layouts. We also present a generalized case where multiple unit road costs are considered in the same stand. 相似文献