Emergent Phenomena Measurement Research Team

We experimentally study electronic states behind emergent phenomena in electron systems, such as high-temperature superconductivity and topological quantum phenomena. For this purpose, we use scanning tunneling microscopes working under combined extreme conditions of very low temperature, high magnetic field and ultra-high vacuum. Modern scanning-tunneling-microscopy technology enables us to obtain a “map of the electronic state” with atomic-scale spatial resolution and energy resolution as high as micro electron volt. We will make and analyze the maps of various materials and try to establish the relationships between material properties and electronic states. We also aim to improve and functionalize the scanning tunneling microscope and pursue the development of novel measurement techniques to discover new emergent phenomena in condensed matter.

Research Fields

Physics / Engineering / Materials Sciences

Research Subjects

• Surface Dirac electrons in topological insulators
• Superconducting-gap structures of high-temperature superconductors
• Development of novel scanning-tunneling-microscopy techniques

Publications

1. T. Hanaguri, et al. Scanning tunneling microscopy/spectroscopy of vortices in LiFeAs, Phys. Rev. B 2012, 85, 214505.
2. Y. Kohsaka, et al. Visualization of the emergence of the pseudogap state and the evolution to superconductivity in a lightly hole-doped Mott insulator, Nature Phys. 2012, 8, 534.
3. T. Hanaguri, K. Igarashi, M. Kawamura, H. Takagi, T. Sasagawa, Momentum-resolved Landau-level spectroscopy of Dirac surface state in Bi2Se3, Phys. Rev. B 2010, 82, 081305(R).
4. T. Hanaguri, S. Niitaka, K. Kuroki, H. Takagi, Unconventional s-Wave Superconductivity in Fe(Se,Te), Science 2010, 328, 474.
5. T. Hanaguri, et al. Coherence Factors in a High-Tc Cuprate Probed by Quasi-particle Scattering off Vortices, Science 2009, 323, 923.
6. T. Hanaguri, et al. Quasiparticle interference and superconducting gap in Ca2-xNaxCuO2Cl2, Nature Phys. 2007 3, 865.
7. T. Hanaguri, et al. Local Tunneling Spectroscopy across a Metamagnetic Critical Point in the Bilayer Ruthenate Sr3Ru2O7, Phys. Rev. Lett. 2007, 99, 057208.
8. Y. Kohsaka, et al. An Intrinsic Bond-Centered Electronic Glass with Unidirectional Domains in Underdoped Cuprates, Science 2007, 315, 1380.
9. T. Hanaguri, Development of high-field STM and its application to the study on magnetically-tuned criticality in Sr3Ru2O7, Journal of Physics: Conference Series 2006, 51, 514.
10. T. Hanaguri, et al. A ‘checkerboard’ electronic crystal state in lightly hole-doped Ca2-xNaxCuO2Cl2, Nature 2004, 430, 1001.