Abstract
We report an optical spectroscopy study on the newly discovered superconductor Cu0.07TiSe2. Consistent with the development from a semimetal or semiconductor with a very small indirect energy gap upon doping TiSe2, it is found that the compound has a low carrier density. Most remarkably, the study reveals a substantial shift of the screened plasma edge in reflectance towards high energy with decreasing temperature. This phenomenon, rarely seen in metals, indicates either a sizable increase of the conducting carrier concentration or/and a decrease of the effective mass of carriers with reducing temperature. We attribute the shift primarily to the latter effect.
Original language | English (US) |
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Article number | 167002 |
Journal | Physical review letters |
Volume | 99 |
Issue number | 16 |
DOIs | |
State | Published - Oct 17 2007 |
All Science Journal Classification (ASJC) codes
- General Physics and Astronomy