TY - JOUR
T1 - Reconstruction of the Fermi surface and the anisotropic excitation gap of Na0.5 CoO2
AU - Arakane, Toshiyuki
AU - Sato, Takafumi
AU - Takahashi, Takashi
AU - Fujii, Takenori
AU - Asamitsu, Atsushi
PY - 2009/8/5
Y1 - 2009/8/5
N2 - 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.
AB - 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.
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U2 - 10.1103/PhysRevB.80.081101
DO - 10.1103/PhysRevB.80.081101
M3 - Article
AN - SCOPUS:70349436987
VL - 80
JO - Physical Review B - Condensed Matter and Materials Physics
JF - Physical Review B - Condensed Matter and Materials Physics
SN - 0163-1829
IS - 8
M1 - 081101
ER -