Development of Acoustic Diode/Switch toward Realization of Phononic Information Processing

2020 Fiscal Year Final Research Report

• Project/Area Number: 17K19035
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Research Field: Nano/Micro science and related fields
• Research Institution: Okayama University
• Principal Investigator: TSURUTA Kenji 岡山大学, 自然科学研究科, 教授 (00304329)
• Co-Investigator(Kenkyū-buntansha): 石川 篤 岡山大学, 自然科学研究科, 助教 (90585994)
• Project Period (FY): 2017-06-30 – 2021-03-31
• Keywords: 音響ダイオード / フォノニック結晶 / 音響トポロジカル絶縁体 / 音響導波路 / 表面弾性波 / 音響メタ表面 / 光学可視化法

Outline of Final Research Achievements

On the basis of phononic band analyses, several prototype structures of "acoustic diode" in which only unidirectional propagation is permitted, have been proposed and their experimental visualization have been performed. In addition, highly efficient acoustic wave guides based on topological edge mode have been demonstrated.
The rectification characteristics of elastic wave based on the hetero-phononic structure, targeted at the beginning, were successfully achieved by optimizing interface structure. On the nonreciprocal acoustic waveguide by applying the external wave modulation, some attempts for the enhancement of modulation effects were examined and their efficiency improvement has been verified. In addition, in the topological acoustic wave guide, it succeeded in the demonstration of the high transmission characteristic beyond our expectation. It thus can become an essential key to the realization of “the phononic information processing system.”

Free Research Field

デバイス物理

Academic Significance and Societal Importance of the Research Achievements

フォノン伝搬に整流性を与えるデバイスは，旧来の電子デバイスによるデジタル情報処理に基づいたIoT/IoE時代の技術ロードマップに，新しい基軸を創成する。つまり，高集積化と高周波数化の極限に達しつつある電子デバイスのロジック・ゲート，フィルタ，基板配線を，電子や光等に新しくフォノンを加えて多元化することにより，ジュール熱等の損失が少ない，より高機能な情報処理システムの技術展開に結び付く。本研究では，それに向け，kHz～THzの幅広い周波数帯で整流効果を発現するいくつかの基本構造の設計と実証に成功した。成果は，Beyond5Gの“フォノン情報処理”実現に向け，極めて重要な一歩であると考える。