Coulomb blockade effects in driven electron transport

We study numerically the influence of strong Coulomb repulsion on the current through molecular wires that are driven by external electromagnetic fields. The molecule is described by a tight-binding model whose first and last site is coupled to a respective lead. The leads are eliminated within a perturbation theory yielding a master equation for the wire. The decomposition into a Floquet basis enables an efficient treatment of the driving field. For the electronic excitations in bridged molecular wires, we find that strong Coulomb repulsion significantly sharpens resonance peaks which broaden again with increasing temperature. By contrast, Coulomb blockade has only a small influence on effects like non-adiabatic electron pumping and coherent current suppression.Comment: 9 pages, 7 figures. Added a plot for temperature dependence of resonance peaks. Published versio

Highly charged ion beam applied to lithography technique (invited)

In various fields of nanotechnology, the importance of nanoscale three-dimensional (3D) structures is increasing. In order to develop an efficient process to fabricate nanoscale 3D structures, we have applied highly charged ion (HCI) beams to the ion-beam lithography (IBL) technique. Ar-ion beams with various charge states (1+ to 9+) were applied to fabricate spin on glass (SOG) and Si by means of the IBL technique. The Ar ions were prepared by a facility built at Kochi University of Technology, which includes an electron cyclotron resonance ion source (NANOGAN, 10 GHz). IBL fabrication was performed as a function of not only the charge state but also the energy and the dose of Ar ions. The present results show that the application of an Ar9+ beam reduces the etching time for SOG and enhances the etching depth compared with those observed with Ar ions in lower charged states. Considering the high-energy deposition of HCI at a surface, the former phenomena can be understood consistently. Also, the latter phenomena can be understood based on anomalously deep structural changes, which are remarkable for glasses. Furthermore, it has also been shown that the etching depth can be easily controlled with the kinetic energy of the Ar ions. These results show the possibilities of the IBL technique with HCI beams in the field of nanoscale 3D fabrication

Charge and spin density response functions of the clean two-dimensional electron gas with Rashba spin-orbit coupling at finite momenta and frequencies

We analytically evaluate charge and spin density response functions of the clean two-dimensional electron gas with Rashba spin-orbit coupling at finite momenta and frequencies. On the basis of our exact expressions we discuss the accuracy of the long-wavelength and the quasiclassical approximations. We also derive the static limit of spin susceptibilities and demonstrate, in particular, how the Kohn-like anomalies in their derivatives are related to the spin-orbit modification of the Ruderman-Kittel-Kasuya-Yosida interaction. Taking into account screening and exchange effects of the Coulomb interaction, we describe the collective charge and spin density excitation modes which appear to be coupled due to nonvanishing spin-charge response function.Comment: 15 pages, 9 figure

Motivation and Its Relationship With Reading Achievement (A Survey at Junior High School No.6 Banda Aceh)

Extrinsic Motivation is a construct resulting in students’ behavior that is encouraged by external rewards. There are many factors that could affect reading comprehension achievement. One of them is reading motivation. Reading motivation and comprehension are two main aspects of creating successful readers. The aim of this research is to investigate the relationship of students’ motivation with their reading achievement. Ninety students were selected as the samples. The data were colected using MRQ questionnaires by Wigfeld Jhon and Guthrie (1996) and reading test which is adopted in English book by The ministry of Education and Culture of the Republic of Indonesia (2014). Pearson Product Moment were used to find out the correlation and influence between the two variables. The result showed that there was significant correlation between reading motivation and reading comprehension achievement with r= 0.652. It is meant that the relationship between reading motivation and reading achievement is high (93,48%). Additionally, female students (59%) had positive motivation than male students (41%)

Characteristics of NERICA in Two Different Ecosystems (Upland and Lowland)

宇都宮大学修士（農学）2007text学位論文 / Thesis or Dissertationthesi