Hidden Order and Dimensional Crossover of the Charge Density Waves in TiSe2
- Univ. of Illinois, Urbana-Champaign, IL (United States). Dept. of Physics, Frederick Seitz Materials Research Lab.; Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Advanced Light Source
- Inst. of Atomic and Molecular Sciences, Taipei (Taiwan)
- Univ. of Illinois, Urbana-Champaign, IL (United States). Dept. of Physics, Frederick Seitz Materials Research Lab.
- Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Advanced Light Source
- Inst. of Atomic and Molecular Sciences, Taipei (Taiwan); National Taiwan Univ., Taipei (Taiwan). Dept. of Physics
- Univ. of Illinois, Urbana-Champaign, IL (United States). Dept. of Physics, Frederick Seitz Materials Research Lab.; National Taiwan Univ., Taipei (Taiwan). Dept. of Physics
Charge density wave (CDW) formation, a key physics issue for materials, arises from interactions among electrons and phonons that can also lead to superconductivity and other competing or entangled phases. The prototypical system TiSe 2, with a particularly simple (2 × 2 × 2) transition and no Kohn anomalies caused by electron-phonon coupling, is a fascinating but unsolved case after decades of research. Our angle-resolved photoemission measurements of the band structure as a function of temperature, aided by first-principles calculations, reveal a hitherto undetected but crucial feature: a (2 × 2) electronic order in each layer sets in at ~232 K before the widely recognized three-dimensional structural order at ~205 K. The dimensional crossover, likely a generic feature of such layered materials, involves renormalization of different band gaps in two stages.
- Research Organization:
- Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC), Basic Energy Sciences (BES)
- Grant/Contract Number:
- AC02-05CH11231; FG02-07ER46383
- OSTI ID:
- 1379594
- Journal Information:
- Scientific Reports, Vol. 6, Issue 1; ISSN 2045-2322
- Publisher:
- Nature Publishing GroupCopyright Statement
- Country of Publication:
- United States
- Language:
- English
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