研究者データベース

橋谷田 俊(ハシヤダ シユン)
電子科学研究所 光科学研究部門
助教

基本情報

所属

  • 電子科学研究所 光科学研究部門

職名

  • 助教

学位

  • 博士(理学)(2017年03月 総合研究大学院大学)

J-Global ID

研究キーワード

  • 円偏光発光   偏光解析   光物性   ナノ光学   ナノ構造体   光学活性   キラリティ   近接場光学顕微鏡   プラズモン   物理化学   

研究分野

  • ナノテク・材料 / 応用物理一般
  • ナノテク・材料 / 分析化学
  • 自然科学一般 / 数理物理、物性基礎
  • ナノテク・材料 / 基礎物理化学
  • 自然科学一般 / 半導体、光物性、原子物理

職歴

  • 2023年04月 - 現在 北海道大学 電子科学研究所 助教
  • 2022年04月 - 2023年03月 中央大学 科研費研究員
  • 2019年04月 - 2022年03月 理化学研究所 基礎科学特別研究員
  • 2019年06月 - 2019年06月 University of Glasgow School of Chemistry Visiting Researcher
  • 2017年04月 - 2019年03月 分子科学研究所 博士研究員
  • 2015年04月 - 2017年03月 日本学術振興会 特別研究員 (DC2)
  • 2016年07月 - 2016年08月 University of Glasgow School of Chemistry Visiting Student
  • 2015年11月 - 2015年12月 University of Glasgow School of Chemistry Visiting Student
  • 2014年10月 - 2015年03月 分子科学研究所 特別奨学生
  • 2014年09月 - 2014年12月 University of Glasgow School of Chemistry Visiting Student

学歴

  • 2012年04月 - 2017年03月   総合研究大学院大学   物理科学研究科   構造分子科学専攻
  • 2007年04月 - 2011年03月   防衛大学校   理工学専攻   応用物理学科

所属学協会

  • 応用物理学会   分子科学会   日本物理学会   

研究活動情報

論文

  • Shun Hashiyada, Yoshito Y. Tanaka
    Review of Scientific Instruments 95 5 053101  2024年05月01日 [査読有り][通常論文]
     
    Helical dichroism (HD), which is defined as the difference in optical absorption between chiral pairs of lights involving left-handed (LH) and right-handed (RH) optical vortices (OVs) carrying orbital angular momentum (OAM), is a promising way to characterize chiral materials. In the current major methods of OV generation using spatial light modulators (SLMs), the speed of OAM switching is typically as slow as 100 Hz, which is comparable to low-frequency noise, making precise chiral detection difficult. Here, we theoretically propose and experimentally demonstrate a rapid modulation of the LH and RH OVs at around 50 kHz. This modulation is achieved through a rapid modulation of circularly polarized lights carrying spin angular momentum (SAM), combined with a SAM–OAM conversion technique. We establish a theory not only for rapid OV modulation but also for HD measurements using the modulated OVs. We experimentally verify the theory using helical phase holograms drawn on a SLM as a pseudo-HD active sample. Our work addresses the limitations of current methods and offers a new avenue for precise HD measurements, paving the way for the development of sensitive chiral-optical spectroscopy techniques.
  • Kensaku Endo, Shun Hashiyada, Tetsuya Narushima, Yoshihiko Togawa, Hiromi Okamoto
    The Journal of Chemical Physics 159 23 2023年12月19日 [査読有り]
     
    Circular dichroism (CD) spectra for pseudo-two-dimensional chiral nanomaterials were systematically investigated and analyzed in relation to the rotational symmetry of the nanomaterials. Theoretically, an ideal two-dimensional chiral matter is CD inactive for light incident normal to the plane if it possesses threefold or higher rotational symmetry. If the matter has two- or onefold rotational symmetry, it should exhibit CD activity, and the CD signal measured from the back side of the matter is expected to be inverted from that measured from the front side. For pseudo-two-dimensional chiral gold nanostructures fabricated on glass substrates using electron beam lithography, matter with fourfold rotational symmetry is found to be CD active, even when special care is taken to ensure that the optical environments for the front and back sides of the sample are equivalent. In this case, the CD signal measured from the back side is found to be almost exactly the same as that measured from the front side. It is revealed that the observed chiro-optical behavior arises from three-dimensional chiral characteristics due to differences in the surface shape between the front and back sides of the structures. For matter that is two- or onefold rotationally symmetric, the CD signal measured from the back side is not coincident with that from the front side. For certain wavelength regions, the CD signals measured from the front side and back side are observed to be similar, while at other wavelengths, the inverted component of the CD signals is found to dominate. The observed CD spectral behavior for reciprocal optical measurement configurations is considered to be determined by a balance between the in-plane isotropic and anisotropic components of the chiral permittivity.
  • Victor Tabouillot, Rahul Kumar, Paula L. Lalaguna, Maryam Hajji, Rebecca Clarke, Affar S. Karimullah, Andrew R. Thomson, Andrew Sutherland, Nikolaj Gadegaard, Shun Hashiyada, Malcolm Kadodwala
    ACS Photonics 2022年10月20日 [査読有り]
  • Junsuke Yamanishi, Hyo-Yong Ahn, Hidemasa Yamane, Shun Hashiyada, Hajime Ishihara, Ki Tae Nam, Hiromi Okamoto
    Science Advances 8 38 eabq2604  2022年09月23日 [査読有り]
     
    When a chiral nanoparticle is optically trapped using a circularly polarized laser beam, a circular polarization (CP)–dependent gradient force can be induced on the particle. We investigated the CP-dependent gradient force exerted on three-dimensional chiral nanoparticles. The experimental results showed that the gradient force depended on the handedness of the CP of the trapping light and the particle chirality. The analysis revealed that the spectral features of the CP handedness–dependent gradient force are influenced not only by the real part of the refractive index but also by the electromagnetic field perturbed by the chiral particle resonant with the incident light. This is in sharp contrast to the well-known behavior of the gradient force, which is governed by the real part of the refractive index. The extended aspect of the chiral optical force obtained here can provide novel methodologies on chirality sensing, manipulation, separation, enantioselective biological reactions, and other fields.
  • Cameron Gilroy, Shun Hashiyada, Kensaku Endo, Affar Shahid Karimullah, Laurence D. Barron, Hiromi Okamoto, Yoshihiko Togawa, Malcolm Kadodwala
    The Journal of Physical Chemistry C 123 24 15195 - 15203 2019年05月 [査読有り][通常論文]
     
    Chiral plasmonic nanostructures enable <= pg detection and characterization of biomaterials. The sensing capabilities are associated with the chiral asymmetry of the near fields, which locally can be greater than equivalent circularly polarized light, a property referred to as superchirality. However, sensing abilities do not simply scale with the magnitude of superchirality. We show that chiral molecular sensing is correlated to the thickness of a nanostructure. This observation is reconciled with a previously unconsidered interference mechanism for the sensing phenomenon. It involves the "dissipation" of optical chirality into chiral material currents through the interference of fields generated by two spatially separated chiral modes. The presence of a chiral dielectric causes an asymmetric change in the phase difference, resulting in asymmetric changes to chiroptical properties. Thus, designing a chiral plasmonic sensor requires engineering a substrate that can sustain both superchiral fields and an interference effect.
  • Shun Hashiyada, Kensaku Endo, Tetsuya Narushima, Yoshihiko Togawa, Hiromi Okamoto
    Journal of Physics: Conference Series 1220 1 012050  2019年05月 [査読有り][通常論文]
     
    © Published under licence by IOP Publishing Ltd. The surface-enhanced chiral-optical spectroscopy is based on the interaction of chiral molecules with chiral electromagnetic near field localized on a chiral plasmonic nanostructure. It is of fundamental importance to reveal the spectral characteristics of chiral near fields for maximizing the chiral interaction. Here we investigate relations between near field and far field polarization characteristics of the chiral plasmonic nanostructures, using electromagnetic simulations. We found that spectral features of chiral near fields created by the nanostructures intercorrelate with those of far field optical rotation. This finding may provide us a method to characterize and design the chiral near field.
  • Shun Hashiyada, Tetsuya Narushima, Hiromi Okamoto
    ACS Photonics 6 3 677 - 683 2019年01月 [査読有り][通常論文]
     
    Chiral optical fields (typified by circularly polarized light) localized on the nanoscale enhance the chiral light-matter interaction, which may provide novel potential applications. This property enables the development of an ultrasensitive method for characterization of chiral molecules and nanoscale magnetic control realized by an all-optical method to interconnect spintronic nano-optical devices. A local chiral light source with switchable handedness or controllable chirality is indispensable for building such applications for practical use. In the current major method used for local chiral light generation, the handedness of the light is controlled by the handedness of the nanomaterial, which is not convenient when we need to change the handedness of the light. We experimentally achieve here generation and active control of a highly chiral local optical field by using a combination of an achiral gold nanorod and achiral linearly polarized optical field. By tilting the azimuth angle for the incident linear polarization relative to the axis of the nanorod, either left- or right-handed circularly polarized local optical fields can be generated. Our work may give us a chance to pioneer analytical applications of chiral optical fields and novel spintronic nano-optical devices.
  • Khai Q Le, Shun Hashiyada, Masaharu Kondo, Hiromi Okamoto
    The Journal of Physical Chemistry C 122 43 24924 - 24932 2018年10月 [査読有り][通常論文]
  • Keigo Masuda, Ryo Shinozaki, Yoshinori Kinezuka, Junhyung Lee, Seigo Ohno, Shun Hashiyada, Hiromi Okamoto, Daisuke Sakai, Kenji Harada, Katsuhiko Miyamoto, Takashige Omatsu
    Optics Express 26 17 22197 - 22207 2018年08月 [査読有り][通常論文]
  • 奥本素子, 橋谷田俊, 高橋明大, 阿部乳坊
    科学教育研究 42 131 - 139 2018年07月 [査読有り][通常論文]
  • Shun Hashiyada, Tetsuya Narushima, Hiromi Okamoto
    ACS Photonics 5 4 1486 - 1492 2018年04月18日 [査読有り][通常論文]
     
    Chiral systems (consisting of materials and incident radiation) respond differently to left- and right-handed circularly polarized light macroscopically. As a consequence, only chiral materials show intrinsic macroscopic optical activity, and only chiral systems generate circularly polarized light from linearly polarized incident light. In the nanoscopic regime, in contrast to this general rule for macroscopic cases, it is theoretically expected that achiral (nonchiral) systems can locally generate circularly polarized fields. Here, we report experimental evidence for that situation in achiral systems consisting of gold nanostructures and linearly polarized incident light. The local circularly polarized fields were visualized by near-field polarimetry imaging, and the spatial features of the observed circularly polarized fields were qualitatively reproduced by a simple dipole model. The present results may provide a novel technique to produce controllable circularly polarized optical fields in nanospaces.
  • Tetsuya Narushima, Shun Hashiyada, Hiromi Okamoto
    CHIRALITY 28 7 540 - 544 2016年07月 [査読有り][通常論文]
     
    Chiral nanostructures show macroscopic optical activity. Local optical activity and its handedness are not uniform in the nanostructure, and are spatially distributed depending on the shape of the nanostructure. In this study we fabricated curved chain nanostructures made of gold by connecting linearly two or more arc structures in a two-dimensional plane. Spatial features of local optical activity in the chain structures were evaluated with near-field circular dichroism (CD) imaging, and analyzed with the aid of classical electromagnetic simulation. The electromagnetic simulation predicted that local optical activity appears at inflection points where arc structures are connected. The handedness of the local optical activity was dependent on the handedness of the local chirality at the inflection point. Chiral chain structures have odd inflection points and the local optical activity distributed symmetrically with respect to structural centers. In contrast, achiral chain structures have even inflection points and showed antisymmetric distribution. In the near-field CD images of fabricated chain nanostructures, the symmetric and antisymmetric distributions of local CD were observed for chiral and achiral chain structures, respectively, consistent with the simulated results. The handedness of the local optical activity was found to be determined by the handedness of the inflection point, for the fabricated chain structures having two or more inflection points. The local optical activity was thus governed primarily by the local chirality of the inflection points for the gold chain structures. The total effect of all the inflection points in the chain structure is considered to be a predominant factor that determines the macroscopic optical activity. (C) 2016 Wiley Periodicals, Inc.
  • 成島 哲也, 橋谷田 俊, 岡本 裕巳
    日本物理学会講演概要集 70 1149 - 1149 一般社団法人日本物理学会 2015年
  • Shun Hashiyada, Tetsuya Narushima, Hiromi Okamoto
    JOURNAL OF PHYSICAL CHEMISTRY C 118 38 22229 - 22233 2014年09月 [査読有り][通常論文]
     
    Since Pasteur's discovery of molecular chirality, which means that the molecule has a nonsuperposable mirror image, the geometrical chirality of a material has been considered the prerequisite for exhibiting circular dichroism (CD, defined as the differential absorption of left and right circularly polarized light) of the structural origin. Here, we report an experimental demonstration of nanoscale local CD activities for achiral (nonchiral) rectangular gold nanostructures. Macroscopic CD spectral measurements of the nanostructure sample did not show any CD activity over the entire range of measured wavelengths, as expected from the achiral shape of the rectangle. In contrast, we found both locally positive and negative CD signals in a single rectangular nanostructure, whose distribution was symmetric about the center of the rectangle, with large CD signals at the corners. The results demonstrate that the established selection rule of optical activity is not valid for local microscopic measurements.
  • Tetsuya Narushima, Shun Hashiyada, Hiromi Okamoto
    ACS PHOTONICS 1 8 732 - 738 2014年08月 [査読有り][通常論文]
     
    We studied the correlation between the geometry and the local optical activity of an "S"-shaped chiral nanostructure composed of two associating achiral "C"-shaped partial structures as one way to elucidate how optical activity develops with the formation of a chiral structure. This chirality formation process models the formation of chiral molecules by association of achiral atoms or functional groups. The local optical activities induced by the association of the achiral nanostructures were investigated using a circular dichroism (CD) nanoimaging technique. The chirality formed with the two approaching achiral partial structures caused enhancement of the local optical activity around the region of their connection when the distance between the achiral partial structures was less than 350 nm. The local optical activity was enhanced even without physical contact of the two partial structures. We therefore concluded that long-range electromagnetic interaction, rather than electronic exchange between the two partial structures, made a major contribution to the optical activity of the chiral nanostructure.
  • 成島 哲也, 橋谷田 俊, 岡本 裕巳
    表面科学 35 6 312 - 318 公益社団法人 日本表面科学会 2014年06月 [査読有り][通常論文]
     
    Nanostructures with chiral shapes show optical activity. The optical activity of the chiral nanostructure may be regarded approximately as an integration of contributions from optical activity of local sites over the entire nanostructure. In this article, we describe our recent experimental efforts to realize 100-nm-scale spatially resolved circular dichroism (CD) imaging. The results of CD imaging for S-shaped gold nanostructure are compared with the macroscopically obtained CD spectra. Local CD signals of both handednesses coexisted in the individual nanostructure, and the spatial distribution of the CD reflected the chiral symmetry of the nanostructure. When the local CD signal is integrated over the entire nanostructure, its value was approximately 1% of the maximum local CD signal, which roughly coincided with the macroscopic CD signal. This indicates that there are possibly prominent local CD signals even if only a tiny CD signal is observed in the macroscopic measurements of optical activity for nanostructured samples.

講演・口頭発表等

その他活動・業績

  • Shun Hashiyada, Kensaku Endo, Tetsuya Narushima, Yoshihiko Togawa, Hiromi Okamoto 2018 Joint Symposia on Optics (Optical Society of America, 2018), paper 30aCJ4 Part F125-OPJ 2018 2018年10月 [査読無し][通常論文]
     
    © 2018 OSJ We investigate relations between near field and far field polarization characteristics of the chiral plasmonic nanostructures, using electromagnetic simulations. We found that the spectral features of chiral near fields created by the nanostructures intercorrelate with those of far field optical rotation. This finding may provide us a method to characterize the chiral near field.
  • Shun Hashiyada, Tetsuya Narushima, Hiromi Okamoto Proceedings of SPIE - The International Society for Optical Engineering 10712 107121S 2018年 [査読無し][通常論文]
     
    We demonstrate here that control of local optical field near a single non-chiral gold nano-rectangle irradiated with linearly polarized light is possible from linearly polarized to nearly pure left- or right-handed circular polarization, by adjusting the angle of the incident polarization relative to the rectangle.
  • Hiromi Okamoto, Shun Hashiyada, Yoshio Nishiyama, Tetsuya Narushima SAP-OSA Joint Symposia 2017 Abstracts (Optical Society of America, 2017), paper 5a_A410_1 Part F78-JSAP 2017 2017年09月 [査読無し][通常論文]
  • Shun Hashiyada, Tetsuya Narushima, Hiromi Okamoto OPTICAL MANIPULATION CONFERENCE 10252 1025214 2017年 [査読無し][通常論文]
     
    We experimentally demonstrate that non-chiral plasmonic nanostructured materials interacting with linearly polarized (non-chiral) light generate elliptically polarized (chiral) optical near-fields in local nano spaces around the materials.

受賞

  • 2017年09月 総合研究大学院大学 総合研究大学院大学研究賞
     
    受賞者: 橋谷田 俊
  • 2016年10月 Student Award, OSJ-OSA Joint Symposia on Plasmonics and Digital Photonics
  • 2016年09月 The Best Poster Presentation Award, The 14th International Conference on Near-Field Optics, Nanophotonics and Related Techniques (NFO-14)
     
    受賞者: 橋谷田 俊
  • 2015年10月 第9回分子科学討論会 優秀ポスター賞
     
    受賞者: 橋谷田 俊
  • 2015年04月 日本化学会 第95春季年会(2015)学生講演賞
     
    受賞者: 橋谷田 俊
  • 2014年03月 日本化学会 東海支部長賞
     
    受賞者: 橋谷田 俊
  • 2014年02月 Asian CORE Winter School Outstanding Oral Award 2014
     
    受賞者: 橋谷田 俊
  • 2013年11月 日本光学会 第9回OPJ ベストプレゼンテーション賞
     
    受賞者: 橋谷田 俊

共同研究・競争的資金等の研究課題

  • 禁制光検出による迅速なキラル近接場光スペクトル測定法の開発
    日本学術振興会:科研費(若手研究)
    研究期間 : 2021年04月 -2023年03月
  • キラル磁気プラズモニクスの開拓
    自然科学研究機構新分野創成センター:先端光科学研究プロジェクト
    研究期間 : 2021年08月 -2022年03月 
    代表者 : 橋谷田俊 戸川欣彦
  • プラズモン光ピンセットで捕捉した分子のキラル分光分析
    日本学術振興会:科研費(若手研究)
    研究期間 : 2019年04月 -2021年03月 
    代表者 : 橋谷田 俊
  • 対称金属ナノ構造と直線偏光を用いた不斉分子の高感度検出
    日本学術振興会:科研費(研究活動スタート支援)
    研究期間 : 2017年08月 -2019年03月 
    代表者 : 橋谷田 俊
  • 金ナノ構造体の強い局所光学活性によるキラル光化学反応場の開拓
    日本学術振興会:科学研究費補助金 特別研究奨励費
    研究期間 : 2015年04月 -2017年03月 
    代表者 : 橋谷田 俊

大学運営

社会貢献活動

  • 期間 : 2013年09月14日 - 2015年11月07日
    役割 : 出演
    その他


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