Superfluid effects in collision between systems with small particle number

The interpretation of the new effect of the superfluidity in reactions with small number of particles is discussed in a simple model where the exact solution is accessible. It is find that the fluctuations of observable with the gauge angle reproduce well the exact fluctuations. Then a method of projection is proposed and tested to determine the transfer probabilities between two superfluid systems.Comment: 4 pages, 4 figures, proceeding of the FUSION17 conferenc

Tunability of Andreev levels via spin-orbit coupling in Zeeman-split Josephson junctions

We study Andreev reflection and Andreev levels $\varepsilon$ in Zeeman-split superconductor/Rashba wire/Zeeman-split superconductor junctions by solving the Bogoliubov de-Gennes equation. We theoretically demonstrate that the Andreev levels $\varepsilon$ can be controlled by tuning either the strength of Rashba spin-orbit interaction or the relative direction of the Rashba spin-orbit interaction and the Zeeman field. In particular, it is found that the magnitude of the band splitting is tunable by the strength of the Rashba spin-orbit interaction and the rength of the wire, which can be interpreted by a spin precession in the Rashba wire. We also find that if the Zeeman field in the superconductor has the component parallel to the direction of the junction, the $\varepsilon$-$\phi$ curve becomes asymmetric with respect to the superconducting phase difference $\phi$. Whereas the Andreev reflection processes associated with each pseudospin band are sensitive to the relative orientation of the spin-orbit field and the exchange field, the total electric conductance interestingly remains invariant.Comment: 10 pages, 8 figure

ガクナイ トピックス ヘンカク ノ ナミノリ サンガッキセイ ニガッキセイ

編集委員のKさんから電話をいただいた。筑波大学も三学期制から二学期制に移行を検討しているのでそれに関する私見を述べよということであった。ながらく三学期制に身を置いてきた私には荷が重い。日々の生活に視点を置いて、創立以来の一大変化について思うところを書かせて頂くことにした。 ..

自己生成・自己組織化ニューラルネットワークを用いた自律移動ロボットの作業環境マップの自動生成

特集 : 「産業におけるソフトコンピューティングに関する国際会議\u2799」発表論文選