Computation of mutual entropy in quantum markov chains

There are several damping phenomena in quantum optics. Such phenomena have been usually explained by open systems. In statistical physics, open system dynamics have been used to study the irreversibility and the approach to equilibrium. In this paper, the dynamical change of the mutual entropy for an open system, frequently studied in the quantum optics literature, is rigorously computed through a model of quantum Markov chain. In particular, the concrete formula of Stinespring expression for such a model is obtained and applied to the derivation of the mutual entropy, and some computational results are presented.     

Wear-resistant magnetic head using amorphous alloy material

An audio recording/playback head using an amorphous (Fe-Co-Ru-Cr) ₇₅(Si-B)₂₅ alloy was developed. Compared with a commercial Sendust head, three excellent features were observed. The wear of the amorphous alloy head when used with γ-Fe₂O ₃ is two-thirds that of the Sendust head. The output level at high-frequency (14 kHz) is 5 dB higher than that of the Sendust head. The bias current for the amorphous alloy head is half that of the Sendust head     

Properties of Quaternary Alloy Magnetic Semiconductor (InGaMn)As Grown on InP

We have studied properties of quaternary alloy magnetic semiconductor (InGaMn)As grown on InP substrates by low-temperature molecular-beam epitaxy (LT-MBE). A large MCD peak whose intensity is larger than 500 mdeg for (InGaMn)As was observed. This peak intensity was about three times larger than that of typical (GaMn)As films. Relatively high Curie temperature of 83 K of [(In_0.53Ga_0.47)_0.88Mn_0.12]As was observed by Hall measurements. The carrier concentration of [(In_0.53Ga_0.47)_0.88Mn_0.12]As was estimated to be more than 1.0 × 10²¹ cm^–3 by using the Curie–Weiss fitting of the Hall coefficient R _H, indicating that more than 40% of Mn atoms are activated. This means that (InGaMn)As has a higher activation ratio of Mn as acceptors than (GaMn)As.     

Narrow spectral linewidth characteristics of monolithic integrated-passive-cavity InGaAsP/InP semiconductor lasers

The spectral linewidth of 1.3 ?m monolithic integrated-passive-cavity (IPC) semiconductor laser is measured by a delayed self-heterodyne technique. It is found that the line-width is narrowed when longitudinal submode is suppressed. The narrowest linewidth obtained so far is 900 kHz at 6 mW output power.     

Lipid-Lowering Effect of Eriocitrin, the Main Flavonoid in Lemon Fruit, in Rats on a High-Fat and High-Cholesterol Diet

ABSTRACT:  Eriocitrin (eriodictyol 7- O -β-rutinoside) is the main flavonoid in lemon fruit. In this study, eriocitrin was investigated for its lowering effect on serum and hepatic lipids in high-fat and high-cholesterol fed rats. Rats in the control group ( N = 6) were fed a 20% lard and 1% cholesterol diet for 21 d, and rats in the 0.35% eriocitrin group ( N = 6) and 0.70% eriocitrin group ( N = 6) were fed a diet supplemented with eriocitrin 0.35% and 0.70%, respectively. The content of hepatic total cholesterol and triglyceride in the eriocitrin group was no different from that of the control group. The total cholesterol, VLDL+LDL, triglyceride, and phospholipid in the serum of the 0.35% eriocitrin group showed significantly lower concentrations than the control group ( P < 0.05), although there was no difference in the HDL concentrations among the groups. The lowering effect of eriocitrin for serum total cholesterol was thought to be caused by a decrease in VLDL+LDL. The 0.35% eriocitrin group was shown to have a significant increase in excretion of fecal bile acid ( P < 0.05) and a tendency for enhanced hepatic m-RNA levels of LDL receptor in comparison with the control group.     

Microstructure of TiO2 and ZnO Films Fabricated by the Sol-Gel Method

Titanium dioxide and zinc oxide films were fabricated by spin-on and dip-coating methods. Both types of films exhibited columnar grains when the single coating was thin, ∼10 nm. The columnar TiO₂ films were dense, as confirmed by their density values calculated from the refractive index and TEM results. The addition of Al cations into the ZnO suppressed grain growth, because Zn had a lower diffusivity in the doped films. The doped ZnO films had nearly the same electrical resistivity as that of the undoped films.     

Preparation of transparent,electrically conducting ZnO film from zinc acetate and alkoxide

Very uniform and transparent zinc oxide thin films doped with aluminium and indium were fabricated by the dip-coating technique using solutions prepared by the ethanolamine method. As starting materials, zinc acetate and zinc n-propoxide were used. Zinc acetate and propoxide are soluble in PrⁱOH in the presence of diethanolamine, although they are hardly soluble without the amine. The prepared solutions were very stable and suitable for dip-coating. Zinc oxide was crystallized by heating above 500 °C, and doping of aluminium and indium retarded the crystallization. The electrical resistivity of the film was decreased by doping with aluminium and indium. The lowest resistivity of 2 × 10^–2 cm was obtained by post-coating treatment in a nitrogen atmosphere.     

Preparation of β-Fesi2 thin film by metal organic chemical vapor deposition using iron-carbonyl and mono-silane

β-FeSi₂ films were deposited at 750 °C by a supplying Fe(CO)₅ and SiH₄ simultaneously during metal organic chemical vapor deposition (CVD). Films could be deposited using this precursors system, even though film deposition was not ascertained by the single supply of Fe(CO)₅. Fe(CO)₅ was probably decomposed in gas phases before it reached to substrate surface. It was suggested that a kind of intermediate reactant which was more stable than Fe(CO)₅ created by the simultaneous supply of Fe(CO)₅ and SiH₄ makes Fe-Si films. Epitaxial β-FeSi₂ films were obtained on Si(111) substrates, and neither carbide nor oxide phases were detected on XRD patterns.