Emergent Phenomena Observation Technology Research Team

Principal Investigator
Outline
Members
Publications
Articles

Principal Investigator

PI Name

Seigo Tarucha

Degree

D.Eng.

Title

Team Leader

Brief Resume

1978	Staff Member at the Basic Research Laboratories of Nippon Tel. & Tel. Corp.
1985	Senior Researcher at the Basic Research Laboratories of Nippon Tel. & Tel. Corp.
1986	Visiting Scientist, Max-Planck-Institute FKF (Stuttgart, Germany)(-1987)
1989	Principal Researcher at the Basic Research Laboratories of Nippon Tel. & Tel. Corp.
1990	Group Leader, Research Group on Electron Transport in Low-Dimensional Semiconductor Structures, NTT Basic Research Laboratories(-1998)
1994	Distinguished Scientist, NTT Basic Research Laboratories (-1998)
1995	Visiting Professor, Technical University of Delft (The Netherlands)
1998	Professor, Department of Physics, University of Tokyo (-2004)
2004	Professor, Department of Applied Physics, University of Tokyo (-2018)
2012	Visiting Professor, Institut Néel CNRS, université Joseph Fourier (France)
2013	Division Director, Quantum Information Electronics Division, RIKEN Center for Emergent Matter Science (-present)
2013	Group Director, Quantum Functional System Research Group, RIKEN Center for Emergent Matter Science (-present)
2018	Deputy Director, RIKEN Center for Emergent Matter Science
2019	Guest Professor, Department of Physics, Tokyo University of Science (-present)
2020	Team Leader, Semiconductor Quantum Information Device Research Team, RIKEN Center for Quantum Computing (-present)
2024	Team Leader, Emergent Phenomena Observation Technology Research Team, RIKEN Center for Emergent Matter Science (-present)

Outline

For observing and analyzing emergent matter phenomena, we use advanced electron microscopy, especially electron holography. Electron holography is a leading-edge observation technology that utilizes interference effects of electron waves and visualizes electromagnetic fields on the nanometer scale. By developing multifunctional transmission electron microscope-specimen holders equipped with plural probes, changes in the electromagnetic fields in and around specimens under applied voltages and magnetic fields are quantitatively investigated. By improving resolutions and precisions of these observation technologies, we can extensively study mechanisms of emergent matter phenomena in newly designed specimens for investigating many-body systems with multiple degrees of freedom.

Research Fields

Materials Science, Physics, Engineering

Keywords

Imaging
Electron microscopy
Lorentz microscopy
Flux quantum
Electron holography
Nanomagnetism

Results

In situ observation of accumulation and collective motion of electrons

Comprehensive understanding of electromagnetic fields requires their visualization both inside and outside of materials. Since electromagnetic fields originate from various motions of electrons, comprehensive study of motions of electrons is of vital importance as well as of significant interest for understanding various emergent phenomena. The purpose of this study is to extend electron holography technology to visualize motions of electrons. By detecting electric field variations through amplitude reconstruction processes for holograms, we have succeeded in visualizing collective motions of electrons around various insulating materials. The lower right figures below show one of our experimental results of visualization of the collective motions of electrons around microfibrils of sciatic nerve tissue. In these reconstructed amplitude images, the bright yellow regions indicate the area where electric field fluctuates due to the motions of electrons. At the initial state (top figure),the electric field variations are not prominent. When the electron irradiation continues, however, bright yellow regions appear and the position of the regions changes gradually between the two branches as indicated by black arrows in the lower figures. These results indicate that the collective motions of electrons can be detected through electric field variation and can be visualized through amplitude reconstruction process for holograms.

Reconstructed amplitude images around microfibrils of sciatic nerve tissue (green).The bright yellow regions indicate the area where electric field fluctuates due to motions of electrons.

Members

Seigo Tarucha	Team Leader	tarucha[at]riken.jp
Ken Harada	Senior Research Scientist
Yoh Iwasaki	Technical Scientist
Keiko Shimada	Technical Staff I

Publications

K. Niitsu, Y. Liu, A. Booth, X. Yu, N. Mathur, M. Stolt, D. Shindo, S. Jin, J. Zang, N. Nagaosa, and Y. Tokura

Geometrically stabilized skyrmionic vortex in FeGe tetrahedral nanoparticles

Nat. Mater. 21, 305–310 (2022)
H. Idzuchi, F. Pientka, K. F. Huang, K. Harada, O. Gul, Y. J. Shin, L. T. Nguyen, N. H. Jo, D. Shindo, R. J. Cava, P. C. Canfield, and P. Kim

Unconventional supercurrent phase in Ising superconductor Josephson junction with atomically thin magnetic insulator

Nat. Commun. 12, 5332 (2021)
D. Shindo, and Z. Akase

Direct observation of electric and magnetic fields of functional materials

Mater. Sci. Eng. R Rep. 142, 100564 (2020)
D. Shindo, T. Tanigaki, and H. S. Park

Advanced Electron Holography Applied to Electromagnetic Field Study in Materials Science

Adv. Mater. 29, 1602216 (2017)
M. Nakamura, F. Kagawa, T. Tanigaki, H. S. Park, T. Matsuda, D. Shindo, Y. Tokura, and M. Kawasaki

Spontaneous Polarization and Bulk Photovoltaic Effect Driven by Polar Discontinuity in LaFeO₃/SrTiO₃ Heterojunctions

Phys. Rev. Lett. 116, 156801 (2016)

Articles

Apr 20, 2018RIKEN RESEARCH Electrical pulses shift the boundaries between magnetic patterns

Electricity can be used to control magnetic patterns in an alloy, opening up the possibility of using them in high-performance devices
Sep 16, 2014RIKEN RESEARCH Magnetism intensified by defects

Electron microscopy reveals how certain nanoscale crystal defects can dramatically intensify ferromagnetism in metal alloys
May 30, 2014RIKEN RESEARCH The shape of spins to come

Electron holography reveals the startling beauty of nanoscale magnetic vortices targeted for future spintronic data storage systems
May 23, 2014RIKEN RESEARCH Split beams reveal the fine print

A holographic technique for imaging electric fields in the vicinity of toner microparticles could lead to higher-quality printing