One-dimensional perturbations of the shift

The structure of isometries on a Hilbert space are well studied. In this paper we study contractions which are one-dimensional perturbations of isometries, in particular, perturbations of the shift operator onH ².     

Outside dislocations generated from phosphorus implanted silicon layers

The growth, movement and nature of outside dislocation, which propagate from heavily phosphorus (>10¹⁵ ions/cm²) implanted (111), (100), and (110) silicon layers into unimplanted outside regions by a compressive strain induced during 1100° C wet O₂ annealing, are investigated using transmission electron microscopy and x-ray diffraction topography. Outside dislocations are formed, mainly on (111) planes., by the glide motion of dislocation networks formed in implanted layers during early annealing. This results in dislocations extending into the unimplanted areas to different degrees, in the order of, from the largest to smallest, (111), (110), and (100) wafers. In (110) wafers, the [001] oriented dislocations in the implanted regions rise to the surface at the implant and unimplant boundary. On the other hand, the [110] dislocations penetrate into the unimplanted region. Two sets of orthogonal 〈110〉 oriented dislocations generated in (100) implanted wafers behave in the same manner as the [001] dislocations in (110) wafers. Some sources of the compressive strain related to the generation of these dislocations are discussed.     

An anomalous emission excited near the absorption edge of pyrene crystals

Emission spectra and decay times of the fluorescence excited at the absorption edge region in pyrene crystals were measured. At liquid nitrogen temperature, the fluorescence under the excitation at 390 nm is considered as the excimer emission and its band peak shifts a little to the short wavelength in comparison with that of the excimer emission under the excitation at 360 nm. The emission decay times under the excitation at the 390 nm and 360 nm are about 155 ns and 180 ns, respectively, at liquid nitrogen temperature. The former decay time changes its value abruptly near 127 K. This abrupt change of the decay time may be due to the phase transition in pyrene crystals.     

Layer-by-layer electrodeposition of copper in the presence of o-phenanthroline, caused by a new type of hidden NDR oscillation with the effective electrode surface area as the key variable

Electrochemical deposition of copper (Cu) from aqueous acidic Cu2+ solutions with o-phenanthroline (o-phen) shows both potential and current oscillations, together with a (partially hidden) N-shaped negative differential resistance (N-NDR), indicating that the oscillations are classified into hidden N-NDR (or HN-NDR) oscillations. The color and the surface morphology of Cu deposits oscillate in synchronization with the potential and current oscillations. Microscopic inspection has shown that dense round Cu leaflets, which look gray, grow in the positive side of the potential oscillation or in the high-current state of the current oscillation, whereas thin Cu leaflets, which look black, grow in the opposite-side stages of the potential and current oscillations, thus finally resulting in a layered Cu deposit with the layer thickness of about 5 microm. The appearance of the NDR is explained to be due to adsorption of the reduced form of a [Cu(II)(o-phen)2]2+ complex, which suppresses the Cu electrodeposition. The increase in the effective electrode surface area by growth of thin Cu leaflets, on the other hand, causes a current increase that can hide the NDR. This NDR-hiding mechanism is of a new type and the present oscillation is regarded as a new-type of HN-NDR oscillator.     

Dual Meissner effect and magnetic displacement currents

The dual Meissner effect is observed without monopoles in quenched SU(2) QCD with Landau gauge fixing. Magnetic displacement currents that are time-dependent Abelian magnetic fields act as solenoidal currents squeezing Abelian electric fields. Monopoles are not always necessary for the dual Meissner effect. A mean-field calculation suggests that the dual Meissner effect through the mass generation of the Abelian electric field is related to a gluon condensate A(a)(mu)A(a)(mu) not equal 0 of mass dimension 2.     

Experimental investigation of a nonideal two-qubit quantum-state filter by quantum process tomography

We used quantum process tomography to investigate and identify the function of a nonideal two-qubit quantum-state filter subject to various degrees of decoherence. We present a simple decoherence model that explains the experimental results and point out that a beam splitter followed by a postselection process is not, as commonly believed, a singlet-state filter. In the ideal case it is a triplet-state filter.