Experimenta study of strrongly correlated phenomena appeared in nano-size materials

2015 Fiscal Year Final Research Report

• Project/Area Number: 25287076
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Partial Multi-year Fund
• Section: 一般
• Research Field: Condensed matter physics I
• Research Institution: Kyushu University
• Principal Investigator: Kawae Tatsuya 九州大学, 工学(系)研究科(研究院), 准教授 (30253503)
• Co-Investigator(Kenkyū-buntansha): INAGAKI Yuji 九州大学, 工学研究院, 助教 (10335458) ; TSUJII Hiroyuki 金沢大学, 学校教育系, 教授 (10392036) ; TANAKA Akinori 有明工業高等専門学校, 一般教育, 准教授 (80274512)
• Project Period (FY): 2013-04-01 – 2016-03-31
• Keywords: ナノワイヤ / 強相関現象 / 強磁性 / 近藤効果 / 超伝導 / 水素トンネル / 水素検出 / ブレークジャンクション

Outline of Final Research Achievements

When the system size is decreased below the characteristic length such as the correlation length, qualitatively different behavior associated with the reduced dimensionality can be observed.
We study ferromagnetic transitions of paramagnetic Pd caused by downsizing via transport measurements. A clear magnetoresistance effect with hysteresis is observed in Pd nanometer-sized constriction below about 30 nanometer. In Ni atomic-scale contact, we observe a Fano resonance with a zero-bias anomaly, likely due to the Kondo effect, which persists in large size constrictions with nearly 50-atom configurations. The results suggest that the Kondo effect and ferromagnetism could coexist in the ferromagnetic nanoconstrictions.
We study H atom absorption and diffusion in Pd nano-contacts immersed in liquid hydrogen using inelastic electron spectroscopy. H absorption develops by applying bias voltage 30-50 mV, which can be understood by quantum tunneling of H atom.

Free Research Field

低温物理学