Distinguishability of complete and unextendible product bases

It is not always possible to distinguish multipartite orthogonal states if only local operation and classical communication (LOCC) are allowed. We prove that we cannot distinguish the states of an unextendible product basis (UPB) by LOCC even when infinite resources (infinite-dimensional ancillas, infinite number of operations). Moreover we give a necessary and sufficient condition for the LOCC distinguishability of complete product bases.Comment: added necessary and sufficient condition for complete product bases, example Lagarias-Shor ten-parties complete basi

An electrical interpretation of mechanical systems via the pseudo-inductor in the Brayton-Moser equations

In this paper an analogy between mechanical and electrical systems is presented, where, in contrast to the traditional analogy, position dependence of the mass inertia matrix is allowed. In order to interpret the mechanical system in an electrical manner, a pseudo-inductor element is introduced to cope with inductor elements with voltage-dependent electromagnetic coupling. The starting point of this paper is given by systems described in terms of the Euler-Lagrange equations. Then, via the introduction of the pseudo-inductor, the Brayton-Moser equations are determined for the mechanical system. © 2005 IEEE.

Exciton-exciton interaction engineering in coupled GaN quantum dots

We present a fully three-dimensional study of the multiexciton optical response of vertically coupled GaN-based quantum dots via a direct-diagonalization approach. The proposed analysis is crucial in understanding the fundamental properties of few-particle/exciton interactions and, more important, may play an essential role in the design/optimization of semiconductor-based quantum information processing schemes. In particular, we focus on the interdot exciton-exciton coupling, key ingredient in recently proposed all-optical quantum processors. Our analysis demonstrates that there is a large window of realistic parameters for which both biexcitonic shift and oscillator strength are compatible with such implementation schemes.Comment: 3 two-column pages, 3 figure

PatentMatrix: an automated tool to survey patents related to large sets of genes or proteins

<p>Abstract</p> <p>Background</p> <p>The number of patents associated with genes and proteins and the amount of information contained in each patent often present a real obstacle to the rapid evaluation of the novelty of findings associated to genes from an intellectual property (IP) perspective. This assessment, normally carried out by expert patent professionals, can therefore become cumbersome and time consuming. Here we present PatentMatrix, a novel software tool for the automated analysis of patent sequence text entries.</p> <p>Methods and Results</p> <p>PatentMatrix is written in the Awk language and requires installation of the Derwent GENESEQ™ patent sequence database under the sequence retrieval system SRS.</p> <p>The software works by taking as input two files: i) a list of genes or proteins with the associated GENESEQ™ patent sequence accession numbers ii) a list of keywords describing the research context of interest (e.g. 'lung', 'cancer', 'therapeutics', 'diagnostics'). The GENESEQ™ database is interrogated through the SRS system and each patent entry of interest is screened for the occurrence of user-defined keywords. Moreover, the software extracts the basic information useful for a preliminary assessment of the IP coverage of each patent from the GENESEQ™ database. As output, two tab-delimited files are generated which provide the user with a detailed and an aggregated view of the results.</p> <p>An example is given where the IP position of five genes is evaluated in the context of 'development of antibodies for cancer treatment'</p> <p>Conclusion</p> <p>PatentMatrix allows a rapid survey of patents associated with genes or proteins in a particular area of interest as defined by keywords. It can be efficiently used to evaluate the IP-related novelty of scientific findings and to rank genes or proteins according to their IP position.</p

Intrinsic electric field effects on few-particle interactions in coupled GaN quantum dots

We study the multiexciton optical spectrum of vertically coupled GaN/AlN quantum dots with a realistic three-dimensional direct-diagonalization approach for the description of few-particle Coulomb-correlated states. We present a detailed analysis of the fundamental properties of few-particle/ exciton interactions peculiar of nitride materials. The giant intrinsic electric fields and the high electron/ hole effective masses give rise to different effects compared to GaAs-based quantum dots: intrinsic exciton-exciton coupling, non molecular character of coupled dot exciton wave function, strong dependence of the oscillator strength on the dot height, large ground-state energy shift for dots separated by different barriers. Some of these effects make GaN/AlN quantum dots interesting candidates in quantum information processing