Reconstruction of the Fermi surface and the anisotropic excitation gap of Na0.5 CoO2

Toshiyuki Arakane, Takafumi Sato, Takashi Takahashi, Takenori Fujii, Atsushi Asamitsu

Research output: Contribution to journalArticlepeer-review

2 Citations (Scopus)


We have performed high-resolution angle-resolved photoemission spectroscopy of Na0.5 CoO2 to elucidate the origin of the two-step phase transition at Tc1 =88 K and Tc2 =53 K. At well below Tc2, we find anisotropic energy-gap opening on the remnant Fermi surface (FS). This gap does not disappear at the metal-insulator transition temperature Tc2 and survives up to Tc1. The remnant FS below Tc2 shows a deviation from the normal-state FS above Tc1, suggesting a possible reconstruction of FS caused by the magnetic ordering.

Original languageEnglish
Article number081101
JournalPhysical Review B - Condensed Matter and Materials Physics
Issue number8
Publication statusPublished - 2009 Aug 5

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics


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