Long-distance single photon transmission from a trapped ion via quantum frequency conversion

Trapped atomic ions are ideal single photon emitters with long-lived internal states which can be entangled with emitted photons. Coupling the ion to an optical cavity enables the efficient emission of single photons into a single spatial mode and grants control over their temporal shape. These features are key for quantum information processing and quantum communication. However, the photons emitted by these systems are unsuitable for long-distance transmission due to their wavelengths. Here we report the transmission of single photons from a single 40Ca+ ion coupled to an optical cavity over a 10 km optical fiber via frequency conversion from 866 nm to the telecom C band at 1530 nm. We observe nonclassical photon statistics of the direct cavity emission, the converted photons, and the 10kmtransmitted photons, as well as the preservation of the photons’ temporal shape throughout. This telecommunication-ready system can be a key component for long-distance quantum communication as well as future cloud quantum computation

Developing a Systematic Subject Instruction Curriculum in Student Teaching Practice: Through the Development and Application of Rubrics

In the practical training at Hiroshima University, we provided practical training guidance using rubrics. Based on the appraisal of the apprentices based on the rubrics and analysis based on the descriptions in the questionnaire and the lesson plan, we found that the rubrics are an effective tool for clarifying the goals to be achieved in the initial stage of apprenticeship and the policies that apprentices should take

Macroscopically uniform and flat lithium thin film formed by electrodeposition using multicomponent additives

It is well-known that the electrodeposition of lithium usually results in the formation of dendrites on the electrode surface. This limits the utilization of metallic lithium as a material for, for example, the negative electrodes of rechargeable batteries. In aqueous solutions, similar dendritic growth of metals is often observed during electrodeposition; however, utilization of multicomponent additives has overcome this shortcoming. Here, we report that the simultaneous utilization of four different additives greatly suppresses the formation of lithium dendrites during electrodeposition in a tetraglyme-based solution. The roles of the additives are discussed, based on the results of electrochemical quartz crystal microbalance measurements and X-ray photoelectron spectroscopy

The Development and Assessment on the Social Studies Handbook for Supporting Teacher’s Lesson Planning and Improvement : A Content Structure of Handbook which can be Applied to Pre-service and In-service Teacher Education

The purposes of this paper are to develop the draft of handbook for planning, teaching and accessing the class of social studies and evaluate effects of the handbook for teacher training and their professional development. The structure of the first draft was designed based on Kolb’s learning theory. The present results suggested that the usefulness of the contents structure was perceived by (1) pre-service teachers and (2) in-service teachers, and the possibility for application was also recognized by the teacher educator as (3) university professor who teach methods courses, (4) senior supervisor who is in charge of designing the professional development programs and (5) younger supervisor who is in charge of tutoring the novice teacher, but they illustrated their different types of the significances, limits and utilization according to their purposes and as well as their responsibility. The authors implicated the alterative design of the handbook based on Korthagen’s reflective learning model for meeting their purposes and solving the structural problems inherit in the handbook

The Quiescent Intracluster Medium in the Core of the Perseus Cluster

Clusters of galaxies are the most massive gravitationally-bound objects in the Universe and are still forming. They are thus important probes of cosmological parameters and a host of astrophysical processes. Knowledge of the dynamics of the pervasive hot gas, which dominates in mass over stars in a cluster, is a crucial missing ingredient. It can enable new insights into mechanical energy injection by the central supermassive black hole and the use of hydrostatic equilibrium for the determination of cluster masses. X-rays from the core of the Perseus cluster are emitted by the 50 million K diffuse hot plasma filling its gravitational potential well. The Active Galactic Nucleus of the central galaxy NGC1275 is pumping jetted energy into the surrounding intracluster medium, creating buoyant bubbles filled with relativistic plasma. These likely induce motions in the intracluster medium and heat the inner gas preventing runaway radiative cooling; a process known as Active Galactic Nucleus Feedback. Here we report on Hitomi X-ray observations of the Perseus cluster core, which reveal a remarkably quiescent atmosphere where the gas has a line-of-sight velocity dispersion of 164+/-10 km/s in a region 30-60 kpc from the central nucleus. A gradient in the line-of-sight velocity of 150+/-70 km/s is found across the 60 kpc image of the cluster core. Turbulent pressure support in the gas is 4% or less of the thermodynamic pressure, with large scale shear at most doubling that estimate. We infer that total cluster masses determined from hydrostatic equilibrium in the central regions need little correction for turbulent pressure.Comment: 31 pages, 11 Figs, published in Nature July