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Telecommunication wavelength with well-developed optical communication technologies and low losses in the waveguide are advantageous for quantum applications. However, an experimental generation of non-classical states called non-Gaussian states at the telecommunication wavelength is still underdeveloped. Here, we generate highly-pure-single-photon states, one of the most primitive non-Gaussian states, by using a heralding scheme with an optical parametric oscillator and a superconducting nano-strip photon detector. The Wigner negativity, the indicator of non-classicality, of the generated single photon state is $-0.228\pm0.004$, corresponded to $85.1\pm0.7\%$ of single photon and the best record of the minimum value at all wavelengths. The quantum-optics-technology we establish can be easily applied to the generation of various types of quantum states, opening up the possibility of continuous-variable-quantum-information processing at telecommunication wavelengths., 10 pages, 6 figures more...

Portable MRI scanners, in which a permanent magnet with a low magnetic field is mounted on a small car, have enabled the performance of MRI examinations in various remote environments. Here, we have modified the portable MRI system to enable the early diagnosis of wrist sports injuries among tennis players. A RF probe specifically designed for the human wrist was developed, and a power supply scheme using a small generator was introduced. The portable MRI system was located at a tennis school and imaging of the wrists of junior tennis players was performed. To demonstrate clinical feasibility, image quality was assessed by a radiologist and clinical evaluations were performed. In most cases, the image quality was sufficient for diagnosis, and triangular fibrocartilage complex damage could be detected. The results indicated that the modified portable MRI system could be applied for an early diagnosis of wrist injuries. more...

Continuous-wave (CW) squeezed light is used in generation of various optical quantum states thus is a fundamental resource of fault-tolerant universal quantum computation using optical continuous variables. To realize a practical quantum computer, a waveguide optical parametric amplifier (OPA) is an attractive CW squeezed light source in terms of its THz-order bandwidth and suitability for modularization. The usages of a waveguide OPA in quantum applications thus far, however, are limited due to the difficulty of the generation of the squeezed light with a high purity. In this paper, we report the first observation of Wigner negativity of the states generated by a heralding method using a waveguide OPA. We generate Schr\"{o}dinger cat states at the wavelength of 1545 nm with Wigner negativity using a quasi-single-mode ZnO-doped periodically poled ${\rm LiNbO_3}$ waveguide module we developed. Wigner negativity is regarded as an important indicator of the usefulness of the quantum states as it is essential in the fault-tolerant universal quantum computation. Our result shows that our waveguide OPA can be used in wide range of quantum applications leading to a THz-clock optical quantum computer., Comment: 10 pages, 5 figures more...

We observed Wigner negativity of Schrödinger cat states generated with a low-loss continuous-wave optical parametric amplifier, paving the way toward fault-tolerant and universal quantum computation with terahertz clock frequency. more...

We propose the first all-optical method for generating arbitrary Gottesman-Kitaev-Preskill states, which fills in the largest missing piece of practical optical quantum computing.

We generate highly-pure single-photon states at the telecommunication wave-length with the best record of the minimum Wigner negativity, paving the way toward the integration of universal quantum computers and constructing quantum networks. more...

We present an architecture of optical quantum computation that does not require optical switches. Our method utilizes quantum teleportation with multimode entanglement making it a scalable architecture that is compatible with the time-domain technology. more...

Fabrication of CNT-dispersed epoxy under various conditions using the ball milling process is performed as a fundamental research on the application of CNT-dispersed resin to CFRP composites. CNT length in compounds and viscosity of CNT-dispersed resin are measured in relation to process conditions. Viscosity characteristics on CNT-dispersed compounds and relationship between CNT length and viscosity are clarified in this paper. more...

Natural and synthetic estrogens from sewage treatment systems are suspected to influence the reproductive health of the animals in the rivers. In this article, we investigated the enzymatic treatment of three estrogens (estrone, 17beta-estradiol, and 17alpha-ethynyletstradiol) by a fungal laccase which oxidize phenolic compounds with dissolved oxygen. The elimination of the estrogenic activities by enzymatic oxidation was demonstrated by medaka vitellogenin assay. In addition, we developed an enzymatic treatment system comprised of beta-D-glucuronidase and the laccase for 17beta-estradiol 3-(beta-D-glucuronide) degradation. The two enzymes eliminated 17beta-estradiol 3-(beta-D-glucuronide) and the intermediate, 17beta-estradiol, efficiently. more...