Joule heating generated by spin current through Josephson junctions

We theoretically study the spin-polarized current flowing through a Josephson junction (JJ) in a spin injection device. When the spin-polarized current is injected from a ferromagnet (FM) in a superconductor (SC), the charge current is carried by the superconducting condensate (Cooper pairs), while the spin-up and spin-down currents flow in the equal magnitude but in the opposite direction in SC, because of no quasiparticle charge current in SC. This indicates that not only the Josephson current but also the spin current flow across JJ at zero bias voltage, thereby generating Joule heating by the spin current. The result provides a new method for detecting the spin current by measuring Joule heating at JJ.Comment: 3 pages, 2 figure

Isotropic, Nematic and Smectic A Phase Behaviour in a Fictitious Field

Phase behaviours of liquid crystals under external fields, conjugate to the nematic order and smectic order, are studied within the framework of mean field approximation developed by McMillan. It is found that phase diagrams, of temperature vs interaction parameter of smectic A order, show several topologically different types caused by the external fields. The influences of the field conjugate to the smectic A phase, which is fictitious field, are precisely discussed.Comment: To be published in J. Phys. Soc. Jpn. vol.73 No.

A doorway to Borromean halo nuclei: the Samba configuration

We exploit the possibility of new configurations in three-body halo nuclei - Samba type - (the neutron-core form a bound system) as a doorway to Borromean systems. The nuclei $^{12}$Be, $^{15}$B, $^{23}$N and $^{27}$F are of such nature, in particular $^{23}$N with a half-life of 37.7 s and a halo radius of 6.07 fm is an excellent example of Samba-halo configuration. The fusion below the barrier of the Samba halo nuclei with heavy targets could reveal the so far elusive enhancement and a dominance of one-neutron over two-neutron transfers, in contrast to what was found recently for the Borromean halo nucleus $^6$He + $^{238}$U.Comment: Accepted for publication in Modern Physics Letters

On the basic mechanism of Pixelized Photon Detectors

A Pixelized Photon Detector (PPD) is a generic name for the semiconductor devices operated in the Geiger-mode, such as Silicon PhotoMultiplier and Multi-Pixel Photon Counter, which has high photon counting capability. While the internal mechanisms of the PPD have been intensively studied in recent years, the existing models do not include the avalanche process. We have simulated the multiplication and quenching of the avalanche process and have succeeded in reproducing the output waveform of the PPD. Furthermore our model predicts the existence of dead-time in the PPD which has never been numerically predicted. For serching the dead-time, we also have developed waveform analysis method using deconvolution which has the potential to distinguish neibouring pulses precisely. In this paper, we discuss our improved model and waveform analysis method.Comment: 4pages, 5figures, To appear in the proceedings of 5th International Conference on New Developments in Photodetection (NDIP08), Aix-les-Bains, France, 15-20 Jun 200

Mossbauer Study on Local Structural Change of Iron Species during Stream-Gasification of Iron-Ioaded Brown Coal

開始ページ、終了ページ: 冊子体のページ付

Sistema de informação de solos brasileiros.

Uma das carências mais marcantes do zoneamento agrícola brasileiro é um repositório de dados de solos brasileiros, razão pela qual a Embrapa vem investindo fortemente para o desenvolvimento de um sistema de informação para suprir essa necessidade. Esse sistema contempla três sub-bases de dados de solos, a saber: uma base de perfis, uma base de fertilidade e uma base cartográfica (dados espaciais).Trabalho apresentado na V Mostra de Trabalhos de Estagiários e Bolsistas, Campinas, out. 2009

Optimal flexibility for conformational transitions in macromolecules

Conformational transitions in macromolecular complexes often involve the reorientation of lever-like structures. Using a simple theoretical model, we show that the rate of such transitions is drastically enhanced if the lever is bendable, e.g. at a localized "hinge''. Surprisingly, the transition is fastest with an intermediate flexibility of the hinge. In this intermediate regime, the transition rate is also least sensitive to the amount of "cargo'' attached to the lever arm, which could be exploited by molecular motors. To explain this effect, we generalize the Kramers-Langer theory for multi-dimensional barrier crossing to configuration dependent mobility matrices.Comment: 4 pages, 4 figure