-
Article type: Cover
2015 Volume 70 Issue 5 Pages
Cover1-
Published: May 05, 2015
Released on J-STAGE: August 21, 2019
JOURNAL
FREE ACCESS
-
Hatsumi Mori
Article type: Article
2015 Volume 70 Issue 5 Pages
335-
Published: May 05, 2015
Released on J-STAGE: August 21, 2019
JOURNAL
FREE ACCESS
-
Article type: Index
2015 Volume 70 Issue 5 Pages
336-337
Published: May 05, 2015
Released on J-STAGE: August 21, 2019
JOURNAL
FREE ACCESS
-
Kenji Fukushima
Article type: Article
2015 Volume 70 Issue 5 Pages
338-339
Published: May 05, 2015
Released on J-STAGE: August 21, 2019
JOURNAL
FREE ACCESS
-
Hiroko Miyahara
Article type: Article
2015 Volume 70 Issue 5 Pages
340-346
Published: May 05, 2015
Released on J-STAGE: August 21, 2019
JOURNAL
FREE ACCESS
Paleoclimate studies have revealed that variations of Earth's climate may be under the control of solar activity, heliospheric environment, and the surrounding condition of our galaxy. One possibility is that galactic cosmic rays are playing important role in climate change by promoting chemical reactions in the atmosphere to produce cloud condensation nuclei and change the albedo of the Earth. We suggest that habitability of extra-solar planets may be also influenced by surrounding space environment and the condition of stellarsphere.
View full abstract
-
Takao Ohta
Article type: Article
2015 Volume 70 Issue 5 Pages
347-355
Published: May 05, 2015
Released on J-STAGE: August 21, 2019
JOURNAL
FREE ACCESS
Recently, the dynamics of active matter has attracted much attention from the view point of nonlinear and nonequilibrium physics. In this article, we discuss the coupling between deformations and migration of an isolated self-propelled particle and the collective dynamics of interacting particles. In the individual dynamics, we found four basic motions, that is, rectilinear, circular, zig-zag and chaotic motions in two dimensions. In the collective dynamics, Chate and his coworkers found, by numerical simulations of the Vicsek model of self-propelled point particles, traveling band structures and giant density fluctuations in a two-dimensional ordered state. The latter is consistent with the theoretical results predicted by Toner and Tu in the coarse-grained hydrodynamical approach. If deformability of particles is taken into account, traveling bands are found to survive head-on collisions.
View full abstract
-
Ai Yamakage, Keiji Yada, Masatoshi Sato, Yukio Tanaka
Article type: Article
2015 Volume 70 Issue 5 Pages
356-361
Published: May 05, 2015
Released on J-STAGE: August 21, 2019
JOURNAL
FREE ACCESS
Doped topological insulators show a variety of superconductivity including topological ones due to their peculiar electronic states and orbital degrees of freedom. We find a transition of energy dispersion of surface Andreev bound states on topological insulators, i.e., Lifshitz transition. This causes anomalous enhancement of tunneling conductance in junction of a normal metal and superconducting topological insulator, which suggests that a recent discovered superconducting topological insulator Cu_xBi_2Se_3 is a three-dimensional topological superconductor.
View full abstract
-
Yusuke Kato, Shohei Watabe
Article type: Article
2015 Volume 70 Issue 5 Pages
362-367
Published: May 05, 2015
Released on J-STAGE: August 21, 2019
JOURNAL
FREE ACCESS
We discuss the underlying relation between superfluidity of a Bose-Einstein condenstate and density fluctuations. In this broad context, we focus on the Hess-Fairbank effect, the persistent current, as well as the Josephson effect. We also show our recent results on the instability of superfluidity in a Josephson system.
View full abstract
-
Sho Sugiura, Akira Shimizu
Article type: Article
2015 Volume 70 Issue 5 Pages
368-373
Published: May 05, 2015
Released on J-STAGE: August 21, 2019
JOURNAL
FREE ACCESS
We have established a new formulation of statistical mechanics based on a pure quantum state, which we call a thermal pure quantum (TPQ) state. A single TPQ state gives all quantities of statistical-mechanical interest. Namely, it gives equilibrium values of mechanical variables, such as the magnetization and correlation function, and those of genuine thermodynamic variables and thermodynamic functions, such as the entropy and free energy. In the TPQ formulation, all thermal fluctuations are included in quantum-mechanical fluctuations. As a consequence, TPQ states have much larger quantum entanglement than the equilibrium density operators of the ensemble formulation. In addition to the foundamental interest of statistical mechanics, we show that the TPQ formulation is very useful in practical computations. This is evidenced by applying the formulation to a frustrated two-dimensional quantum spin system.
View full abstract
-
[in Japanese]
Article type: Article
2015 Volume 70 Issue 5 Pages
374-375
Published: May 05, 2015
Released on J-STAGE: August 21, 2019
JOURNAL
FREE ACCESS
-
[in Japanese]
Article type: Article
2015 Volume 70 Issue 5 Pages
376-378
Published: May 05, 2015
Released on J-STAGE: August 21, 2019
JOURNAL
FREE ACCESS
-
[in Japanese]
Article type: Article
2015 Volume 70 Issue 5 Pages
378-379
Published: May 05, 2015
Released on J-STAGE: August 21, 2019
JOURNAL
FREE ACCESS
-
[in Japanese], [in Japanese]
Article type: Article
2015 Volume 70 Issue 5 Pages
380-382
Published: May 05, 2015
Released on J-STAGE: August 21, 2019
JOURNAL
FREE ACCESS
-
[in Japanese], [in Japanese], [in Japanese], [in Japanese]
Article type: Article
2015 Volume 70 Issue 5 Pages
382-385
Published: May 05, 2015
Released on J-STAGE: August 21, 2019
JOURNAL
FREE ACCESS
-
[in Japanese]
Article type: Article
2015 Volume 70 Issue 5 Pages
386-387
Published: May 05, 2015
Released on J-STAGE: August 21, 2019
JOURNAL
FREE ACCESS
-
[in Japanese]
Article type: Article
2015 Volume 70 Issue 5 Pages
388-
Published: May 05, 2015
Released on J-STAGE: August 21, 2019
JOURNAL
FREE ACCESS
-
[in Japanese]
Article type: Article
2015 Volume 70 Issue 5 Pages
389-
Published: May 05, 2015
Released on J-STAGE: August 21, 2019
JOURNAL
FREE ACCESS
-
[in Japanese]
Article type: Article
2015 Volume 70 Issue 5 Pages
389-390
Published: May 05, 2015
Released on J-STAGE: August 21, 2019
JOURNAL
FREE ACCESS
-
2015 Volume 70 Issue 5 Pages
390
Published: 2015
Released on J-STAGE: August 21, 2019
JOURNAL
FREE ACCESS
-
Article type: Appendix
2015 Volume 70 Issue 5 Pages
391-393
Published: May 05, 2015
Released on J-STAGE: August 21, 2019
JOURNAL
FREE ACCESS
-
Article type: Appendix
2015 Volume 70 Issue 5 Pages
394-
Published: May 05, 2015
Released on J-STAGE: August 21, 2019
JOURNAL
FREE ACCESS
-
[in Japanese]
2015 Volume 70 Issue 5 Pages
395-
Published: May 05, 2015
Released on J-STAGE: August 21, 2019
JOURNAL
FREE ACCESS
-
2015 Volume 70 Issue 5 Pages
396-397
Published: May 05, 2015
Released on J-STAGE: August 21, 2019
JOURNAL
FREE ACCESS
-
2015 Volume 70 Issue 5 Pages
398-399
Published: May 05, 2015
Released on J-STAGE: August 21, 2019
JOURNAL
FREE ACCESS
-
Article type: Appendix
2015 Volume 70 Issue 5 Pages
400-401
Published: May 05, 2015
Released on J-STAGE: August 21, 2019
JOURNAL
FREE ACCESS
-
2015 Volume 70 Issue 5 Pages
402-
Published: May 05, 2015
Released on J-STAGE: August 21, 2019
JOURNAL
FREE ACCESS