Fast polarimetry system for the application to spin quantum non-demolition measurement

We report the development of a fast pulse polarimeter for the application to quantum non-demolition measurement of atomic spin (spin QND). The developed system was tunable to the atomic resonance of a ytterbium atom and has narrow laser line width suitable for spin QND. Using the developed polarimeter, we successfully demonstrated the measurement of the vacuum noise, with 10⁶ to 10⁷ photon number per pulse. PACS 42.25.Ja; 42.50.Lc; 42.55.Px     

A single-electron circuit as a discrete dynamical system

A single-electron circuit can be operated as a discrete dynamical system because it changes its internal state discontinuously because of electron tunneling. To confirm this idea, we designed a sample circuit for discrete dynamical operation and confirmed by computer simulation that the circuit successfully generated a sequence of discrete-time outputs by following a return map. The concept of discrete dynamical systems will be useful in developing new functional systems that consist of quantum devices and nanostructures.     

Development and use of a multichannel (e,2e) spectrometer for electron momentum densities of molecules

We have developed an (e,2e) spectrometer with the introduction of modern multiparameter techniques. In particular, the high sensitivity achieved by simultaneous detection in energy and momentum is remarkable, opening up the possibilities of more precise and more advanced studies on the electronic structure of atoms and molecules. To illustrate some of the features, an overview of our recent results is presented. Highlights are applications to collision dynamics of H₂ and development of a method for a complete three-dimensional mapping of electron momentum densities in gaseous molecules. Both of these studies are based on the high sensitivity of the spectrometer.     

Doubly coprime representation of linear systems and its application to simultaneous stabilization

This paper develops a new representation theory of multivariabletime-invariant linear systems based on the well-known coprimefactorizations of their transfer matrices. This representationfully uses the algebraic structure of coprime factorizations,and hence has a number of advantages for describing variousproperties of linear systems in simpler and/or more compactforms than the usual transfer matrix representation. In theframework of this new representation theory, various stabilityand stabilizability properties of linear systems are characterizedand finally a simultaneous stabilization problem for a givenset of linear systems is examined.     

Growth of the Bi2O3 thin films under atmospheric pressure by means of halide CVD

Films of Bi₂O₃ were grown on glass substrate under atmospheric pressure by means of halide chemical vapour deposition (AP-HCVD) using BiI₃ and O₂ as the starting materials. In the XRD diffractogram of the film a strong diffraction peak appears at 27.91° assigned to the (111) diffraction of the δ-Bi₂O₃ with cubic structure. X-ray pole figure suggested that the 〈111〉 direction of the film is perpendicular to the substrate surface, while the 〈110〉 axis directs towards all directions parallel to the substrate surface. It is for the first that δ-Bi₂O₃ film was prepared on glass substrate.     

121Sb Mössbauer spectroscopic study of a series of organoantimony(III) compounds

A systematic study of organoantimony(III) compounds, SbR₃, was attempted in view of the effect on Mössbauer parameters of the substituent on the aromatic ring. The Mössbauer parameters obtained in frozen organic solutions reflected the electronic effect caused by the characteristics of the substituents, electron donative or attractive, at the para position on the aromatic ring.     

The mechanism of the reaction of elementary astatine with organic solvents

The mechanism of the reaction of elementary astatine with benzene, toluene and monochlorobenzene were studied by means of radiogaschromatography. The reaction proceeds in two steps with benzene and toluene. In Step 1 the chemical bond of At₂ is cleaved by the disintegration of either astatine and the remained astatine reacts immediately with solvent. At Step 2 the compound produced at Step 1 is started to decompose by the decay of astatine. But this mechanism could not be applied to the astatine-monochlorobenzene system.