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Vortex Matter Research Using Electron Microscopy: Memorial to Akira Tonomura

Ken Harada¹, Nobuyuki Osakabe², and Yoshimasa A. Ono³

¹Hitachi Central Research Laboratory, Hatoyama, Saitama 350-0395, Japan
²Hitachi Central Research Laboratory, Kokubunji, Tokyo 185-8601, Japan
³FIRST Tonomura Project, Japan Science and Technology Agency, Hatoyama,
Saitama 350-0395, Japan
e-mail: [email protected], [email protected],
[email protected]

Abstract - Using electron holography and “coherent beam” Lorentz microscopy, Akira Tonomura studied vortex physics in metal and high-temperature superconductors for more than 20 years. The new methodology he introduced involved coherent electron waves from cold emission (field emission) sources and their quantum mechanical phase shifts. Using 300 kV and 1 MV electron microscopes Tonomura and his collaborators studied dynamic behavior of vortices in metal superconductors, Pb and Nb, and in high-temperature superconductors, YBa₂Cu₃O_7-δ and Bi₂Sr₂CaCu₂O_8+δ . In this memorial paper for Akira Tonomura the static and dynamic vortex behavior in superconductors is reviewed based on the group’s results.

Keywords - vortex, superconductivity, electron holography, Lorentz microscopy

Received: July 15, 2012; Accepted July 25, 2012 .
Reference No CR30; Categories 1, 2, 4.