Characterization methods dedicated to nanometer-thick hBN layers

Hexagonal boron nitride (hBN) regains interest as a strategic component in graphene engineering and in van der Waals heterostructures built with two dimensional materials. It is crucial then, to handle reliable characterization techniques capable to assess the quality of structural and electronic properties of the hBN material used. We present here characterization procedures based on optical spectroscopies, namely cathodoluminescence and Raman, with the additional support of structural analysis conducted by transmission electron microscopy. We show the capability of optical spectroscopies to investigate and benchmark the optical and structural properties of various hBN thin layers sources

Unitary Representations of Unitary Groups

In this paper we review and streamline some results of Kirillov, Olshanski and Pickrell on unitary representations of the unitary group \U(\cH) of a real, complex or quaternionic separable Hilbert space and the subgroup \U_\infty(\cH), consisting of those unitary operators $g$ for which g - \1 is compact. The Kirillov--Olshanski theorem on the continuous unitary representations of the identity component \U_\infty(\cH)_0 asserts that they are direct sums of irreducible ones which can be realized in finite tensor products of a suitable complex Hilbert space. This is proved and generalized to inseparable spaces. These results are carried over to the full unitary group by Pickrell's Theorem, asserting that the separable unitary representations of \U(\cH), for a separable Hilbert space \cH, are uniquely determined by their restriction to \U_\infty(\cH)_0. For the $10$ classical infinite rank symmetric pairs $(G,K)$ of non-unitary type, such as (\GL(\cH),\U(\cH)), we also show that all separable unitary representations are trivial.Comment: 42 page

Tom Burns, Elcio Cornelson, Volker Jaeckel, and Luis Gustavo Vieira, eds. War and Literature: Looking Back on 20th Century Armed Conflicts. Stuttgart: Ibidem Verlag, 2014.

Review of Tom Burns, Elcio Cornelson, Volker Jaeckel, and Luis Gustavo Vieira, eds. War and Literature: Looking Back on 20th Century Armed Conflicts. Stuttgart: Ibidem Verlag, 2014

Design principles for secure integration of information

The purpose of this paper is to twofold. Firstly, we will show how various conflicts which may arise in a mediated system can be handled by means of annotated constraint logic. Secondly, we will briefly discuss some security related issues in a mediator architecture and possible solutions which can be implemented within our system