KUMAGAI GROUP


  1. Ultrafast Nano-imaging and Optical Control of Hyperbolic Phonon Polaritons at hBN/WS2 Heterojunctions
    K. Kamada, K. Shinokita, F. Zeng, R. Kitaura, K. Watanabe, T. Taniguchi, A. Paarmann, M. Shibuta, T. Kumagai*, J. Nishida*
    Nano Letters ASAP
    DOI: 10.1021/acs.nanolett.6c02448


  2. Controlling electron transfer channels in a plasmonic scanning tunneling microscope junction under light excitation
    C. Lin*, X. Liu, T. Kumagai, M. Müller, M. Wolf, S. Liu*
    Nanoscale 18, 11310 (2026)
    DOI: 10.1039/d5nr05496f


  3. Thermodynamics and Kinetics of Two-Dimensional H2 Gas on Ag (111) Studied by Tip-Enhanced Raman Spectroscopy
    S. Liu, Y. Park, J. Yoshinobu, T. Kumagai, M. Wolf, A. Shiotari*
    Nano Letters 26, 6868 (2026)
    DOI: 10.1021/acs.nanolett.6c00325


  4. Point-Contact Tip-Enhanced Raman Spectroscopy: Picoscale Light–Matter Interactions within Plasmonic Cavities
    (Invited Mini-Review)
    T. Kumagai*, K. Miwa, B. Cirera
    Nano Letters 25, 15449 (2025)
    DOI: 10.1021/acs.nanolett.5c04045


  5. Ultrafast infrared nano-imaging of local electron-hole dynamics in CVD-grown single-walled carbon nanotubes
    J. Nishida*, K. Otsuka, T. Minato, Y. K. Kato, T. Kumagai*
    Science Advances 11, eadv9584 (2025)
    DOI: 10.1126/sciadv.adv958


  6. Scattering near-field optical microscopy at 1-nm resolution using ultralow tip oscillation amplitudes
    A. Shiotari*, J. Nishida, A. Hammud, F. Schulz, M. Wolf, T. Kumagai, M. Müller
    Science Advances 11, eadu1415 (2025)
    DOI: 10.1126/sciadv.adu1415


  7. Picocavity-Enhanced Raman Spectroscopy of Physisorbed H2 and D2 Molecules
    A. Shiotari*, S. Liu1, G. Trenins, T. Sugimoto, M. Wolf, M. Rossi*, T. Kumagai*
    Physical Review Letters 134, 206901 (2025)
    DOI: 10.1103/PhysRevLett.134.206901
    Press release: Picometric Spectroscopy of Hydrogen Molecules in Atomic-Scale Cavities [Link]


  8. Quantitative comparison of local field enhancement from tip-apex and plasmonic nanofocusing excitation via plasmon-assisted field emission resonances
    C. Lin*, J. Li, G. Li, W. Luo, S.Liu, A. Hammud, Y. Xia, A. Pan, M. Wolf, M. Müller, T. Kumagai*
    Nanoscale 17, 7164 (2025)
    DOI: 10.1039/D4NR04262J


  9. Plasmonic Light Emission by Inelastic Charge Transport in Ultrathin Zinc Oxide/Metal Heterostructures
    H. Wiedenhaupt, F. Schulz, Luis E. P. López, A. Hammud, Y. Park, A. Shiotari, T. Kumagai, M. Wolf, M. Müller*
    Nano Letters 25, 7, 2870 (2025)
    DOI: 10.1021/acs.nanolett.4c06099


  10. Ultrafast Nano-Imaging of Spatially Modulated Many-Body Dynamics in CVD-Grown Monolayer WS2
    Y. Wang, J. Nishida*, K. Nakamoto, X, Yang, Y. Sakuma, W. Zhang, T. Endo, Y. Miyata, T. Kumagai*
    ACS Photonics 12, 207 (2025)
    DOI: 10.1021/acsphotonics.4c01545


  11. Atomic-precision control of plasmon-induced single-molecule switching in a metal–semiconductor nanojunction
    Y. Park*, I. Hamada, A. Hammud, T.Kumagai, M. Wolf, A. Shiotari*
    Nature Communications 15, 6709 (2024)
    DOI: 10.5281/zenodo.10890118


  12. Single-molecule tip-enhanced Raman spectroscopy of C60 on the Si(111)-(7 × 7) surface
    B. Cirera*, S. Liu, Y. Park, I. Hamada, M. Wolf, A. Shiotari, T. Kumagai
    Phys. Chem. Chem. Phys. 26, 21325 (2024)
    DOI: 10.1039/D4CP01803F


  13. Sub-Tip-Radius Near-Field Interactions in Nano-FTIR Vibrational Spectroscopy on Single Proteins
    J. Nishida*, A. Otomo, T. Koitaya, A. Shiotari, T. Minato, R. Iino, T. Kumagai*
    Nano Lett. 24, 836 (2024)
    DOI: 10.1021/acs.nanolett.3c03479
    Press release: Observing Single Protein with Infrared Nanospectroscopy


  14. Continuous-Wave Multiphoton-Induced Electron Transfer in Tunnel Junctions Driven by Intense Plasmonic Fields
    C. Lin*, F. Krecinic, H. Yoshino, A. Hammud, A. Pan, M. Wolf, M. Müller*, T. Kumagai*
    ACS Photonics 10, 3637 (2023)
    DOI: 10.1021/acsphotonics.3c00714


  15. Metastability in the Insulator–Metal Transition for Individual Vanadium Dioxide Nanoparticles
    K. Nishikawa, J. Nishida*, M. Yoshimura, K. Nakamoto, T. Kumagai, Y. Watanabe*
    J. Phys. Chem. C 127, 16485 (2023)
    DOI: 10.1021/acs.jpcc.3c02151


  16. Inelastic Light Scattering in the Vicinity of a Single-Atom Quantum Point Contact in a Plasmonic Picocavity
    S. Liu, F. P. Bonafe, H. Appel, A. Rubio, M. Wolf, T. Kumagai*
    ACS Nano 17, 10172 (2023)
    DOI: 10.1021/acsnano.3c00261


  17. Nanoscale coherent phonon spectroscopy
    S. Liu, A. Hammud, I. Hamada, M. Wolf, M. Müller, T. Kumagai*
    Science Advances 8 (42), eabq5682 (2022)
    DOI: 10.1126/sciadv.abq5682


  18. Joule Heating in Single-Molecule Point Contacts Studied by Tip-Enhanced Raman Spectroscopy
    B. Cirera, M. Wolf, T. Kumagai*
    ACS nano 16 (10), 16443-16451 (2022)
    DOI: 10.1021/acsnano.2c05642


  19. Femtosecond Thermal and Nonthermal Hot Electron Tunneling Inside a Photoexcited Tunnel Junction
    N. Martín Sabanés, F. Krecinic, T. Kumagai, F. Schulz, M. Wolf, M. Müller*
    ACS nano 16 (9), 14479-14489 (2022)
    DOI: 10.1021/acsnano.2c04846


  20. Nanoscale Heating of an Ultrathin Oxide Film Studied by Tip-Enhanced Raman Spectroscopy
    S. Liu, M. Wolf, T. Kumagai*
    Physical Review Letters 128 (20), 206803 (2022)
    DOI: 10.1103/PhysRevLett.128.206803