[4/25] The 16th “AIMR Seminar”
Speaker
Prof. Takafumi Sato (PI of AIMR, Tohoku University)
Title
Unveiling Hidden Electronic States of Quantum Materials with Spatially-Resolved ARPES
Date
April 25 (Fri), 2025, 14:00–14:55 on Japan Time
Venue
Seminar Room, 2nd floor, AIMR Main Building
Abstract
Electronic band structures underpin the physical properties of crystalline solids. Angle resolved photoemission spectroscopy (ARPES), grounded in the external photoelectric effect, has long been the workhorse for mapping these structures in quantum materials ranging from high temperature superconductors to topological insulators. Recent advances—most notably spin and time resolved ARPES—now allow us to probe spin textures and ultrafast electron dynamics.
The newest frontier is spatially resolved ARPES, which extends these capabilities to samples and devices that were previously out of reach [1]. In this talk, I will survey the rapid progress of the technique and spotlight several key results:
- Hard to cleave bulk crystals — direct band structure determination for bulk crystals with strong 3D bonding [2].
- Micron sized powders — electronic mapping of quantities too small for conventional ARPES [3].
- Domain resolved studies — identification of polar, magnetic, and structural domains that govern exotic phenomena, including
- one dimensional edge states in topological chiral crystals [4],
- intertwined charge order and superconductivity in kagome lattices [5],
- antiferromagnetic topological insulator [6], and
- near room temperature ferromagnetism in atomic-layer materials[7].
Finally, I will discuss how next generation synchrotron facilities such as NanoTerasu will integrate spatially resolved ARPES into a broader quantum materials toolkit, enabling routine visualization of hidden electronic states with sub micron precision.
- [1] H. Zhang et al., Nature Reviews Methods Primers 2, 54 (2022).
- [2] T. Osumi et al., Phys. Rev. B 109, 115102 (2024).
- [3] K. Sugawara et al., Nano Lett. 23, 1673 (2023).
- [4] K. Nakayama et al., Nature 631, 54 (2024).
- [5] K. Nakayama et al., Phys. Rev. X 12, 011001 (2022).
- [6] A. Honma et al., Nat. Commun. 14, 7396 (2023).
- [7] C.-W. Chuang et al., Nat. Commun., in press (2025).
AIMR Seminars and Tea Time
We hold AIMR Seminars and Friday Tea Time as part of the initiative to promote fusion research.
Seminars are presented by AIMR researchers and visiting scientists who provide a wide range of hot topics from materials science to mathematics. The aims of the AIMR Seminar are to build up mutual understanding, communication, and discussions of each other’s research fields.
Weekly held Friday Tea Time is where AIMR researchers and staff members can relax and talk freely while drinking coffee. Expectations of stimulating conversation may arise among the researchers and leading to new research.
From 2024, active fusion research through synergistic effects from AIMR Seminars and Friday Tea Time will be promoted.
Past AIMR Seminar
About Tea Time Talk
As part of an event during Friday Tea Time, AIMR has been hosting lectures by famed researchers and the archives up to 2023 are listed below:
| 43rd | July 21, 2023 | Prof. Feral Temelli (University of Alberta, Canada) |
|---|---|---|
| 42nd | June 30, 2023 | Dr. Douglas Brumley (The University of Melbourne, Australia) |
| 41st | Mar. 28, 2023 | Prof. Motomu Tanaka (Physical Chemistry of Biosystems, Institute of Physical Chemistry, Heidelberg University, Germany) |
| 40th | Nov. 10, 2022 | Prof. Masahiro Yoshimura (National Cheng Kung University, Taiwan) |
| 39th | June 17, 2022 | Prof. Rana Mohtadi (Toyota Research Institute of North America) |
| 38th | June 17, 2022 | Prof. Michael Hirscher (Max-Planck-Institute for Intelligent Systems, Germany) |
| 37th | June 3, 2022 | Prof. Reiko Oda (French National Centre for Scientific Research) |
| 36th | May 28, 2021 | Prof. Magda Titirici (Imperial College London, U.K.) |
| 35th | Mar. 26, 2021 | Prof. Yaroslav Blanter (Kavli Institute of Nanoscience, Delft University of Technology) |
| 34th | Oct. 23, 2020 | Dr. Kazuhito Tsukagoshi (PI:WPI-MANA, NIMS & AIMR) |
| 33rd | July 17, 2020 | Prof. Kaoru Tamada (IMCE, Kyushu University & AIMR) |
| 32nd | Jan. 17, 2020 | Prof. Miho Yamauchi (I2CNER / Kyushu University & AIMR) |
| 31st | Jan. 17, 2020 | Prof. Mickaël Lallart (INSA Lyon, Université de Lyon) |
| 30th | Oct. 25, 2019 | Assoc. Prof. Frédéric Gillot (Department of Solid Mechanics, Mechanical Eng. and Civil Eng., École Centrale de Lyon) |
| 29th | July 12, 2019 | Prof. Qian Niu (Department of Physics, The University of Texas at Austin) |
| 28th | May 17, 2019 | Prof. Damien Fabrègue (INSA Lyon, France / ELyT MaX Lab at Tohoku University) |
| 27th | Dec. 14, 2018 | Prof. Yukitoshi Motome (Department of Applied Physics, The University of Tokyo, Japan) |
| 26th | July 13, 2018 | Dr. Shimpei Ono (Central Research Institute of Electric Power Industry, Japan) |
| 25th | May 11, 2018 | Dr. Pierre-Antoine Geslin (Mateis lab, INSA Lyon/CNRS / ELyTMaX Lab at Tohoku University / Institute for Materials Research, Tohoku University) |
| 24th | Apr. 27, 2018 | Prof. Masaru Tsukada (AIMR, Tohoku University) |
| 23rd | Dec. 8, 2017 | Prof. Jean-Yves Cavaillé (INSA Lyon, France / ELyT MaX Lab at Tohoku University) |
| 22nd | July 28, 2017 | Prof. Nicolas Mary (INSA Lyon, France / ELyT MaX Lab at Tohoku University) |
| 21st | July 21, 2017 | Prof. Gael Sebald (INSA Lyon, France / ELyT MaX at Tohoku University) |
| 20th | July 7, 2017 | Prof. Arun Bansil (Northeastern University) |
| 19th | June 30, 2017 | Dr. Takeshi Nakanishi (AIST-Tohoku U Mathematics for Advanced Materials Open Innovation Laboratory (MathAM-OIL)) |
| 18th | June 23, 2017 | Prof. Denis Arčon (Jožef Stefan Institute, Slovenia) |
| 17th | Apr. 28, 2017 | Prof. Ayumi Hirano (AIMR, Tohoku University) |
| 16th | Nov. 29, 2016 | Dr. David Guy Austing (National Research Council Canada, Canada) |
| 15th | Sept. 30, 2016 | Prof. C. Suryanarayana (University of Central Florida, U.S.A.) |
| 14th | June 17, 2016 | Prof. Tomoteru Fukumura (AIMR, Tohoku University) |
| 13th | May 13, 2016 | Prof. Jean-Yves Cavaillé (ELyT MaX (Joint Lab at Tohoku University), University of Lyon, France) |
| 12th | June 26, 2015 | Dr. B. Muralidharan (Indian Institute of Technology Bombay, India) |
| 11th | June 27, 2014 | Prof. Michael B. Santos (The University of Oklahoma, U.S.A.) |
| 10th | Nov. 19, 2013 | Dr. Pawel Hawrylak (National Research Council Canada, Canada) |
| 9th | Oct. 1, 2013 | Dr. Yuan T. Lee (Nobel laureate in Chemistry, Academia Sinica of Taiwan) |
| 8th | June 28, 2013 | Dr. Bjorn Mysen (Geophysical Laboratory, Carnegie Institution for Science, U.S.A.) |
| 7th | Apr. 12, 2013 | Prof. Yiming Li (National Chiao Tung University, Taiwan) |
| 6th | Jan. 18, 2013 | Prof. Tomasz Dietl (Polish Academy of Sciences, Poland) |
| 5th | Aug. 31, 2012 | Prof. John H. Perepezko (University of Wisconsin-Madison, U.S.A.) |
| 4th | Aug. 17,2012 | Prof. Alain Reza Yavari (Grenoble Institute of Technology, France) |
| 3rd | Aug. 10, 2012 | Prof. Alan Lindsay Greer (University of Cambridge, U.K.) |
| 2nd | July 6, 2012 | Prof. Winfried Teizer (Texas A&M University, U.S.A.) |
| 1st | May 25, 2012 | Prof. Thomas P. Russell (The University of Massachusetts Amherst, U.S.A.) |