Squeezing at 946nm with periodically-poled KTiOPO_4

We report generation of squeezed vacuum in sideband modes of continuous-wave light at 946 nm using a periodically poled KTiOPO_4 crystal in an optical parametric oscillator. At the pump power of 250 mW, we observe the squeezing level of -5.6+/-0.1 dB and the anti-squeezing level of +12.7+/-0.1 dB. The pump power dependence of the observed squeezing/anti-squeezing levels agrees with the theoretically calculated values when the phase fluctuation of locking is taken into account.Comment: 3 pages, 3 figures, submitted to Optics Letter

Generation of continuous-wave broadband Einstein-Podolsky-Rosen beams using periodically-poled lithium niobate waveguides

Continuous-wave light beams with broadband Einstein-Podolsky-Rosen correlation (Einstein-Podolsky-Rosen beams) are created with two independent squeezed vacua generated by two periodically-poled lithium niobate waveguides and a half beam splitter.Comment: 4 pages, 3 figure

High-fidelity teleportation beyond the no-cloning limit and entanglement swapping for continuous variables

We experimentally demonstrate continuous-variable quantum teleportation beyond the no-cloning limit. We teleport a coherent state and achieve the fidelity of 0.70$\pm$0.02 that surpasses the no-cloning limit of 2/3. Surpassing the limit is necessary to transfer the nonclassicality of an input quantum state. By using our high-fidelity teleporter, we demonstrate entanglement swapping, namely teleportation of quantum entanglement, as an example of transfer of nonclassicality.Comment: revised version, 4 pages, 4 figure

A state-space based design of generalized minimum variance controller equivalent to transfer-function based design

Proposes a generalized minimum variance controller (GMVC) using a state-space approach. The controller consists of a state feedback and a reduced-order observer with poles at z=0. A coprime factorization of the state-space based controller is also obtained. It is shown that the GMVC designed by state-space approach is equivalent to the GMVC given by solving Diophantine equations and a polynomial approach. The equivalence is proved by comparing coprime factorizations of the two controllers. From the results of the paper, it may be possible to apply advanced design schemes given by state-space control theory to the design of GMVC</p

An extension of generalized minimum variance control for multi-input multi-output systems using coprime factorization approach

This paper proposes a new generalized minimum-variance controller (GMVC) having new design parameters by using the coprime factorization approach for a multi-input multi-output (MIMO) case. The method is directly extended from a conventional GMVC and used to construct the controller; it needs to solve only one Diophantine equation as in the conventional method. In this paper, by using double-coprime factorization, a simple formula for the closed-loop system given by the parametrized controller is obtained; and using the formula, it is proved that the closed-loop characteristic from the reference signal to plant output is independent of the selection of the design parameters and the poles of the controller can be chosen by the design parameters without changing the closed-loop system</p

A state-space based design of generalized minimum variance controller equivalent to transfer-function based design

Proposes a generalized minimum variance controller (GMVC) using a state-space approach. The controller consists of a state feedback and a reduced-order observer with poles at z=0. A coprime factorization of the state-space based controller is also obtained. It is shown that the GMVC designed by state-space approach is equivalent to the GMVC given by solving Diophantine equations and a polynomial approach. The equivalence is proved by comparing coprime factorizations of the two controllers. From the results of the paper, it may be possible to apply advanced design schemes given by state-space control theory to the design of GMVC</p

Histochemical demonstration of three types of muscle fibers of the intercostal muscles. A study on oxidative enzymes

Since the classic work of Ranvier, it is well known that the mammalian striated muscle is composed of two types of muscle fibers, i. e., the red and white muscle fibers. In the previous paper1 it has been reported that the limb muscle fibers of mammals can be divided into three types from their activities of the histochemically demonstrable oxidative enzymes. Namely, the small red muscle fibers had a higher activity of oxidative enzymes, the large white muscle fibers a lower activity and the third type of muscle fibers being called &#34;medium fiber&#34; or &#34;intermediate fiber&#34; showed an intermediate activity between those of the red and white muscle fibers.</p

Nickel bis­muth boride, Ni23-xBixB6 [x = 2.44 (1)]

The τ-boride Ni23-xBixB6 [x = 2.44 (1)] adopts a ternary variant of the cubic Cr23C6-type structure, with Ni8 cubes and Ni12 cubocta­hedra arranged in a NaCl-type pattern. Two of the four independent metal sites (8c, 3m symmetry; 4a, m m symmetry) are occupied by a mixture of Ni and Bi atoms in a 0.106 (6):0.894 (6) and a 0.350 (7):0.650 (7) ratio, respectively