Not So SuperDense Coding - Deterministic Dense Coding with Partially Entangled States

The utilization of a $d$-level partially entangled state, shared by two parties wishing to communicate classical information without errors over a noiseless quantum channel, is discussed. We analytically construct deterministic dense coding schemes for certain classes of non-maximally entangled states, and numerically obtain schemes in the general case. We study the dependency of the information capacity of such schemes on the partially entangled state shared by the two parties. Surprisingly, for $d>2$ it is possible to have deterministic dense coding with less than one ebit. In this case the number of alphabet letters that can be communicated by a single particle, is between $d$ and 2d. In general we show that the alphabet size grows in "steps" with the possible values $d, d+1, ..., d^2-2$. We also find that states with less entanglement can have greater communication capacity than other more entangled states.Comment: 6 pages, 2 figures, submitted to Phys. Rev.

Is Communication Complexity Physical?

Recently, Brassard et. al. conjectured that the fact that the maximal possible correlations between two non-local parties are the quantum-mechanical ones is linked to a reasonable restriction on communication complexity. We provide further support for the conjecture in the multipartite case. We show that any multipartite communication complexity problem could be reduced to triviality, had Nature been more non-local than quantum-mechanics by a quite small gap for any number of parties. Intriguingly, the multipartite nonlocal-box that we use to show the result corresponds to the generalized Bell inequality that manifests maximal violation in respect to a local hidden-variable theory

Entanglement and the Speed of Evolution in Mixed States

Entanglement speeds up evolution of a pure bipartite spin state, in line with the time energy uncertainty. However if the state is mixed this is not necessarily the case. We provide a counter example and point to other factors affecting evolution in mixed states, including classical correlations and entropy

Peranan Penyidik Kepolisian Resor Siak Dalam Mengungkap Tindak Pidana Menggunakan Senjata Api

In the beginning the use of firearms is only allowed for certain apparatus with the provisions and controls are tight, especially in the field of defence and security. As the development era that has begun to lack of surveillance conducted by law enforcement officers in cracking down on rampant circulation up illegal firearms that have been circulating in the community, which resulted in the occurrence of the crime using firearms. Licensing the ownership of firearms have been regulated in such a way in terms of legislation. Based on the description that has been described above, the author argues for the analytically descriptive regarding the role of the investigating of the Siak Resort Police in exposing the crime using firearms.This legal research suggests the outline of three problems as follows: 1) how did the Siak Resort Police investigator's role in exposing the crime using firearms?, 2) what are the obstacles of the Siak Resort Police investigator in exposing the crime using firearms?, and 3) how the Siak Resort Police investigator attempt to overcome the obstacles in exposing the crime using firearms? This research use sociological, juridical methods which are: applying research approaches to the study of perception and behavior of legal persons (human and legal entity) and the community as well as the effectiveness of the enactment of positive law in the community, where the author direct research on the location or place that is examined in order to give a complete and clear picture of the problems in a thorough the Siak Resort Police investigator's role in uncovering the crime using firearms.Legal research is then analyzed the role of the Siak Resort Police investigator in exposing the crime using firearms where the leading sector on Reserse Criminal Unit (Satreskrim) at the Siak Resort Police (Polres Siak) and coordinate with other entities such as the Security Intelligence Unit (Satintelkam) and the active participation of all elements of society, the obstacles encountered is the number of elements in the community who still feel frightened to report any event or incident a criminal offence who uses a firearm, and concrete efforts made by Police investigators, among others in the form of the Siak Resort Police construction and/or socialization to all elements of society to improve environmental safety systems in order to cope with the increasing swakarsa crime using firearms

Topological Wilson-loop area law manifested using a superposition of loops

We introduce a new topological effect involving interference of two meson loops, manifesting a path-independent topological area dependence. The effect also draws a connection between quark confinement, Wilson-loops and topological interference effects. Although this is only a gedanken experiment in the context of particle physics, such an experiment may be realized and used as a tool to test confinement effects and phase transitions in quantum simulation of dynamic gauge theories.Comment: Superceding arXiv:1206.2021v1 [quant-ph

Mode-Wise Entanglement of Gaussian States

We address the decomposition of a multi-mode pure Gaussian state with respect to a bi-partite division of the modes. For any such division the state can always be expressed as a product state involving entangled two-mode squeezed states and single mode local states at each side. The character of entanglement of the state can therefore be understood modewise; that is, a given mode on one side is entangled with only one corresponding mode of the other, and therefore the total bi-partite entanglement is the sum of the modewise entanglement. This decomposition is generally not applicable to all mixed Gaussian states. However, the result can be extended to a special family of "isotropic" states, characterized by a phase space covariance matrix with a completely degenerate symplectic spectrum.Comment: 4 pages, RevTex4. Replaced with revised version with reference added to a previous related paper. Minor typographical errors correcte

Continuous input nonlocal games

We present a family of nonlocal games in which the inputs the players receive are continuous. We study three representative members of the family. For the first two a team sharing quantum correlations (entanglement) has an advantage over any team restricted to classical correlations. We conjecture that this is true for the third member of the family as well.Comment: Journal version, slight modification