Insulator-metal transition in CaTiO3 quantum dots induced by ultrafast laser pulses  

作　　者：Tong Liu Hong Zhang Xin-Lu Cheng 刘彤;张红;程新路(College of Physics,Sichuan University,Chengdu 610065,China;Key Laboratory of High Energy Density Physics and Technology of Ministry of Education,Sichuan University,Chengdu 610065,China)

机构地区：[1]College of Physics,Sichuan University,Chengdu 610065,China [2]Key Laboratory of High Energy Density Physics and Technology of Ministry of Education,Sichuan University,Chengdu 610065,China

出　　处：《Chinese Physics B》2020年第5期509-515,共7页中国物理B（英文版）

基　　金：Project supported by the National Key Research and Development Program of China(Grant No.2017YFA0303600);the National Natural Science Foundation of China(Grant Nos.11974253 and 11774248).

摘　　要：According to time-dependent density functional theory(TDDFT),we study the interactions between ultra-fast laser pulses and two kinds of calcium titanate quantum dots(PCTO-QDs and MCTO-QDs).Under the action of localized field effect,ultrafast laser can induce quantum dots to make the transition from insulator to metal.The PCTO-QDs are ultimately metallic,while the MCTO-QDs are still insulator after experiencing metal state.This is bacause the stability of the unsaturated atoms in the outermost layer of PCTO-QDs is weak and the geometric configuration of MCTO-QDs as a potential well will also reduce the damage of laser.Moreover,laser waveforms approaching to the intrinsic frequency of quantum dots tend to cause the highest electron levels to cross the Fermi surface.In this paper,it is reported that the insulating quantum dots can be transformed into metal by adjusting the intensity and frequency of laser.The importance of local morphology is emphasized by comparing two kinds of CTO-QDs.More importantly,it is an important step to identify the potential properties of perovskite materials.

关 键 词：ultra-fast laser CaTiO3 QDs metallic transformation 

分 类 号：O471.1[理学—半导体物理]