Anomalous anisotropic exciton temperature dependence in rutile TiO2

被引：9

作者：

Baldini, Edoardo ^{[1
,2
]}

Dominguez, Adriel ^{[3
]}

Chiodo, Letizia ^{[4
]}

Sheveleva, Evgeniia ^{[5
]}

Yazdi-Rizi, Meghdad ^{[5
]}

Bernhard, Christian ^{[5
]}

Rubio, Angel ^{[3
,6
]}

Chergui, Majed ^{[1
,2
]}

机构：

[1] Ecole Polytech Fed Lausanne, Lab Ultrafast Spect, ISIC, CH-1015 Lausanne, Switzerland

[2] Ecole Polytech Fed Lausanne, Lausanne Ctr Ultrafast Sci LACUS, CH-1015 Lausanne, Switzerland

[3] Max Planck Inst Struct & Dynam Matter, D-22761 Hamburg, Germany

[4] Univ Campus Biomed Roma, Unit Nonlinear Phys & Math Modeling, Dept Engn, Via Alvaro Portillo 21, I-00128 Rome, Italy

[5] Univ Fribourg, Dept Phys, Chemin Musee 3, CH-1700 Fribourg, Switzerland

[6] Univ Basque Country, Dept Fis Mat, Ave Tolosa 72, E-20018 San Sebastian, Spain

来源：

PHYSICAL REVIEW B | 2017年 / 96卷 / 04期

基金：

瑞士国家科学基金会; 欧洲研究理事会;

关键词：

ENERGY-GAP; GREENS-FUNCTION; SEMICONDUCTORS; CONSTANTS; CRYSTALS; ANATASE;

D O I：

10.1103/PhysRevB.96.041204

中图分类号：

T [工业技术];

学科分类号：

08 ;

摘要：

Elucidating the details of electron-phonon coupling in semiconductors and insulators is a topic of pivotal interest, as it governs the transport mechanisms and is responsible for various phenomena such as spectral-weight transfers to phonon sidebands and self-trapping. Here, we investigate the influence of the electron-phonon interaction on the excitonic peaks of rutile TiO2, revealing a strong anisotropic polarization dependence with increasing temperature, namely, an anomalous blue shift for light polarized along the a axis and a conventional red shift for light polarized along the c axis. By employing many-body perturbation theory, we identify two terms in the electron-phonon interaction Hamiltonian that contribute to the anomalous blue shift of the a-axis exciton. Our approach paves the way to a complete ab initio treatment of the electron-phonon interaction and of its influence on the optical spectra of polar materials.

引用

页数：5