The critical role of hot carrier cooling in optically excited structural transitions  

作　　者：Wen-Hao Liu Jun-Wei Luo Shu-Shen Li Lin-Wang Wang 

机构地区：[1]State Key Laboratory of Superlattices and Microstructures,Institute of Semiconductors,Chinese Academy of Sciences,Beijing,China [2]Center of Materials Science and Optoelectronics Engineering,University of Chinese Academy of Sciences,Beijing,China [3]Beijing Academy of Quantum Information Sciences,Beijing,China [4]Materials Science Division,Lawrence Berkeley National Laboratory,Berkeley,CA,USA

出　　处：《npj Computational Materials》2021年第1期1061-1066,共6页计算材料学（英文）

基　　金：The work in China was supported by the Key Research Program of Frontier Sciences,CAS under Grant No.ZDBS-LY-JSC019;the Strategic Priority Research Program of the Chinese Academy of Sciences under Grant No.XDB43020000;the National Natural Science Foundation of China(NSFC)under Grant Nos.11925407 and 61927901;L.-W.W.was supported by the Director,Office of Science(SC),Basic Energy Science(BES),Materials Science and Engineering Division(MSED),of the US Department of Energy(DOE)under Contract No.DE-AC02-05CH11231 through the Materials Theory program(KC2301).

摘　　要：The hot carrier cooling occurs in most photoexcitation-induced phase transitions(PIPTs),but its role has often been neglected in many theoretical simulations as well as in proposed mechanisms.Here,by including the previously ignored hot carrier cooling in real-time time-dependent density functional theory(rt-TDDFT)simulations,we investigated the role of hot carrier cooling in PIPTs.Taking IrTe2 as an example,we reveal that the cooling of hot electrons from the higher energy levels of spatially extended states to the lower energy levels of the localized Ir–Ir dimer antibonding states strengthens remarkably the atomic driving forces and enhances atomic kinetic energy.These two factors combine to dissolute the Ir–Ir dimers on a timescale near the limit of atomic motions,thus initiating a deterministic kinetic phase transition.We further demonstrate that the subsequent cooling induces nonradiative recombination of photoexcited electrons and holes,leading to the ultrafast recovery of the Ir–Ir dimers observed experimentally.These findings provide a complete picture of the atomic dynamics in optically excited structural phase transitions.

关 键 词：TRANSITION EXCITED TRANSITIONS 

分 类 号：O562[理学—原子与分子物理]