Abstract
Using high-resolution photoemission spectroscopy (ARPES), we present a systematic study of the insulating cobaltates. A single-particle gap opening suggests that due to the material's unique topology an anisotropic particle-hole instability is present. Unlike conventional density waves, charge stripes or band insulators, the onset of the gap depends on the quasiparticle's quantum coherence which occurs well below the symmetry-breaking temperature of the crystal. Results are found to be in good agreement with bulk resistivity, specific heat and optical measurements.
Original language | English (US) |
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Pages (from-to) | 1007-1009 |
Number of pages | 3 |
Journal | Physica B: Condensed Matter |
Volume | 403 |
Issue number | 5-9 |
DOIs | |
State | Published - Apr 1 2008 |
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Electrical and Electronic Engineering
Keywords
- Frustrated systems
- Metal-insulator transition
- Mott insulator
- Sodium cobaltate
- Triangular lattice