Frontier Research Institute for Interdisciplinary Sciences
Tohoku University

Taketoshi Minato "Tunneling Desorption of Single Hydrogen on the Surface of Titanium Dioxide", ACS Nano (America Chemical Society) A research team comprising scientists from Tohoku University (FRIS and AIMR), RIKEN, the University of Tokyo, Chiba University and University College London have discovered a new chemical reaction pathway on titanium dioxide (TiO2), an important photocatalytic material.  The reaction mechanism, reported in ACS Nano, involves the application of an electric field that narrows the width of the reaction barrier, thereby allowing hydrogen atoms to tunnel away from the surface. This opens the way for the manipulation of the atomic-scale transport channels of hydrogen, which could be important in hydrogen storage. Hydrogen has been put forward as a clean and renewable alternative to the burning of hydrocarbons and one of the great challenges of our day is to find an efficient way to store and transport it.  The team used scanning tunneling microscopy (STM) to directly visualize single hydrogen ions, a common atomic defect on TiO2. In STM, the surface structure of a solid surface is observed on the atomic scale by scanning a sharp probe across the surface and monitoring the tunneling current. Minato and his collaborators were able to desorb individual hydrogen ions from the surface by using the STM probe to apply electrical pulses to the hydrogen. The pulse generates an electric field as well as injecting electrons into the sample. By using a new theoretical approach, the team confirmed that rather than reducing the reaction barrier height, the electric field reduces the width of the barrier, thereby allowing the hydrogen to desorb by quantum tunneling.  Lead author Prof. Taketoshi Minato (Tohoku Univ. and RIKEN, currently Kyoto University) commented that “The new reaction pathway could be exploited in nanoscale switching devices and hydrogen storage technology. For instance, electric fields could be used to extract hydrogen from a TiO2-based storage device”. Publication Details Authors：Taketoshi Minato, Seiji Kajita, Chi-Lun Pang, Naoki Asao, Yoshinori Yamamoto, Takashi Nakayama, Maki Kawai, and Yousoo Kim Title：Tunneling Desorption of Single Hydrogen on the Surface of Titanium Dioxide Journal：ACS Nano (America Chemical Society) (Volume and pages：details to be added later) DOI：10.1021/acsnano.5b01607 Contact :  Professor Taketoshi Minato International Advanced Research and Education Organization  Office of Society-Academia Collaboration for Innovation  Kyoto University Email: minato.taketoshi.5x(at)kyoto-u.ac.jp  Tel: +81-774-38-4942 (Formerly of Tohoku University and RIKEN) Press Release :  Tohoku University EurekAlert!

Kenji Toma（Creative Interdisciplinary Research Division） "NEUTRINO AND COSMIC-RAY EMISSION AND CUMULATIVE BACKGROUND FROM RADIATIVELY INEFFICIENT ACCRETION FLOWS IN LOW-LUMINOSITY ACTIVE GALACTIC NUCLEI", 2015 ApJ 806 159 Kenji TOMA has proposed a new theoretical model explaining the origin of recently observed high-energy astrophysical neutrinos in collaboration with Shigeo KIMURA and Kohta MURASE (Pennsylvania State University). Neutrino is one of the elementary particles and well known since Prof. KOSHIBA received a Nobel Prize on the first detection of astrophysical neutrinos. Recently, neutrinos with about 10 millions times higher energies than detected by Prof. KOSHIBA have been observed with a huge detector in Antarctica. Their origin is being a mystery. K. TOMA has proposed a new theoretical model in which they are produced in the vicinities of super massive black holes at the center of ordinary galaxies. This model also implies new possible studies investigating physical conditions around the black holes and history of galaxy evolutions with neutrino observations. This work has been published in “Astrophysical Journal” of the American Astronomical Society. Shigeo S. Kimura, Kohta Murase and Kenji Toma 2015 ApJ 806 159 doi:10.1088/0004-637X/806/2/159

"Pre-Symposium of HeKKSaGOn on Mechanobiology" co-organized as "FRIS 8th seminar" "Pre-Symposium of HeKKSaGOn on Mechanobiology" co-organized as "FRIS 8th seminar"  Venue: FRIS seminar hall About HeKKSaGOn:The German-Japanese University Consortium  

Naoya Onizawa（Creative Interdisciplinary Research Division） Dr. Onizawa received the "Best Paper Finalist" at 20th IEEE International Symposium on Asynchronous Circuits and Systems (ASYNC2014). Assistant Professor Dr. Naoya Onizawa received the "Best Paper Finalist" at 20th IEEE International Symposium on Asynchronous Circuits and Systems(ASYNC2014) held on May 12-14, 2014. This award is given to a paper nominated to Best Paper Award at ASYNC2014. The paper title is "A Compact Soft-Error Tolerant Asynchronous TCAM Based on a Transistor/Magnetic-Tunnel-Junction Hybrid Dual-Rail Word Structure". New Paradigm VLSI System Laboratory for Brainware Systems Research Institute of Electrical Communication, Tohoku University Naoya Onizawa, Assistant Professor E-mail:nonizawa@m.tohoku.ac.jp