Attractive Coulomb interaction, temperature-dependent hybridization, and natural circular dichroism in 1T- TiSe2

C. W. Chuang, Y. Tanaka, M. Oura, K. Rossnagel, A. Chainani

研究成果: Article同行評審

摘要

We study the electronic structure of single crystal 1T-TiSe2 using temperature (T)-dependent soft x-ray photoemission spectroscopy (PES) and natural circular dichroism (NCD) across the charge-density-wave (CDW) transition at Tcdw∼200 K. We investigate detailed changes in energy positions and widths of the Ti 2p and Se 3d core-level spectra across Tcdw. The Ti 2p-3d-resonant PES shows a clear Ti 3d character two-hole correlation satellite in the valence band. A Cini-Sawatzky analysis indicates an effective attractive two-hole Coulomb interaction energy Udd =-1.3 eV. This attractive Coulomb energy is significantly larger than the known energy scale of excitonic correlations (< 100 meV) in 1T-TiSe2. On-resonant T-dependent measurements indicate that the strongly hybridized Ti 3d-Se 4p bands show increased hybridization in the CDW phase. On-resonant valence band spectra show a finite, possibly experimental geometry-related NCD of the states at and near the Fermi level which do not show T dependence across Tcdw. Given the presence of excitonic effects and the periodic lattice distortion, our results suggest that theoretical models need to take into account the attractive Coulomb interaction and hybridization changes for a complete understanding of the CDW in 1T-TiSe2.

原文English
文章編號195102
期刊Physical Review B
102
發行號19
DOIs
出版狀態Published - 2020 十一月 2

All Science Journal Classification (ASJC) codes

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics

指紋 深入研究「Attractive Coulomb interaction, temperature-dependent hybridization, and natural circular dichroism in 1T- TiSe2」主題。共同形成了獨特的指紋。

引用此