Optimal state estimation for d-dimensional quantum systems

We establish a connection between optimal quantum cloning and optimal state estimation for d-dimensional quantum systems. In this way we derive an upper limit on the fidelity of state estimation for d-dimensional pure quantum states and, furthermore, for generalized inputs supported on the symmetric subspace.Comment: 3 page

Spuler, Bertold

Spuler, Bertold (b. Karlsruhe, Germany, 5 December 1911; d. Hamburg, 6 March 1990), scholar of East European history and Oriental studies. Among his many publications are important works on the history of the Iranian lands from the 7th century CE onwards

UV laser radiation for microstructuring of photostructurable glasses

Photostructurable glasses are important materials for applications in microsystems. They enable structures with high aspect ratios and a high dependability of mechanical, optical and chemical properties in a large range of temperatures. The exposure of photostructurable glasses to UV laser radiation, as a rapid prototyping technique, is an alternative method to the exposure by a mask aligner. Α photostructurable glass (FS21) was exposed to UV laser radiation of the wavelengths 248, 308 and 355 nm. Investigated was the influenee of the exposure parameters wavelength of laser radiation and energy density on structuring results such as crystallization depth, lateral geometry of crystallized areas, structure of crystallized areas and etch angle for single pulse exposure

The Influence of Various Factors on the Progress in Training of International Learners of the Preparatory Department (on the Example of the Course "Computer Science")

The task of research different factors affecting on the progress in training of students is actual. Two main factors as training the course in native language and knowledge of the language in which the course is studied were considered to solve this problem. The research is aimed at learners of the Preparatory Department studying in a non-native language (Russian) and takes into account the characteristics of such contingent of students. The study was made in the course "Computer science" with the help of methods of mathematical statistics. This research was conducted to improve the methods and to change the approaches in teaching the pre-university programs

Phase covariant quantum cloning

We consider an N -> M quantum cloning transformation acting on pure two-level states lying on the equator of the Bloch sphere. An upper bound for its fidelity is presented, by establishing a connection between optimal phase covariant cloning and phase estimation. We give the explicit form of a cloning transformation that achieves the bound for the case N=1, M=2, and find a link between this case and optimal eavesdropping in the quantum cryptographic scheme BB84.Comment: 9 pages, 1 figur