Ultrafast femtosecond laser control of electron dynamics in two-dimensional strong spin-orbit coupling materials

二维强自旋轨道耦合材料中电子动力学的超快飞秒激光控制

• 批准号: 22K13991
• 负责人: Hashmi Arqum
• 金额: $ 2.41万
• 依托单位: National Institutes for Quantum Science and Technology
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Early-Career Scientists
• 财政年份: 2022
• 资助国家: 日本
• 起止时间: 2022-04-01 至 2024-03-31
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-22K13991/
• 关键词: Spin-orbit interactions; TDDFT; Nonlinear optics; Ultrafast; 2D material; Time dependent DFT; Spintronics; Valleytronics; Ultrafast dynamics

By using Time-dependent density functional theory (TDDFT) based on the Maxwell-TDDFT scheme, the combined classical Maxwell plus time-dependent Kohn-Sham (TDKS) equations are used to describe the propagation of electromagnetic fields. Regarding the ultrafast electron dynamics in 2D layers of Transition metal dichalcogenides, I investigated the carrier dynamics in terms of valley polarization in WSe2 monolayer via single and two-color laser field.The valley selection rules suggest that linearly polarized light couples equally to both valleys and valley polarization cannot be achieved by a linearly polarized field. My study is focused on the above-mentioned argument and we aimed to induce valley asymmetry by linearly polarized pulses which are considered not achievable by a linearly polarized field.It is possible to create an asymmetric laser field by mixing a fundamental frequency and its second harmonic. The two pulses intensity ratio and the relative carrier-envelope phase (CEP) control the valley polarization. I compared the valley polarization results of two-color laser scheme results with the single color pulse. I found that the valley polarization via two-color control exceeds the single-color scheme by 1.2 times as the two-colors field exhibits more asymmetry in its temporal shape. The results reveal a convenient new path toward the optical control of valley pseudospins.

通过使用基于麦克斯韦 - tddft方案的时间依赖性密度函数理论（TDDFT），使用的经典麦克斯韦和时间依赖性的kohn-sham（TDKS）方程用于描述电磁场的传播。关于过渡金属二核苷二维层中的超快电子动力学，我通过单个和两种颜色的激光场在WSE2单层中的山谷极化方面调查了载体动力学。山谷选择规则表明，线性极化的光夫人均等地对谷和谷地极化均不能通过通过线性极化实现。我的研究集中在上述论点上，我们的目的是通过线性极化脉冲诱导山谷不对称，这被认为是线性极化场无法实现的。可以通过混合基本频率及其第二个谐波来创建不对称的激光场。两个脉冲强度比和相对载体 - 内玻璃相（CEP）控制山谷极化。我将两色激光方案结果的山谷极化结果与单色脉冲进行了比较。我发现，随着两色田间表现出更多的不对称性，通过两色控制的山谷极化超过了单色方案的1.2倍。结果揭示了通往山谷伪单胞胶光学控制的方便新路径。

项目成果

Weak and Strong Field Control of Valley Polarization in WSe2 Monolayer

WSe2单层谷极化的弱场和强场控制

• 发表时间: 2022
• 作者: Takanobu Kirihara;Hajime Susa;Takashi Hosokawa;Tomoya Kinugawa;Hashmi Arqum
• 通讯作者: Hashmi Arqum

Optical Field Control of Electron Dynamics in WSe2 Monolayer

WSe2 单层电子动力学的光场控制

• 发表时间: 2022
• 作者: Takanobu Kirihara;Hajime Susa;Takashi Hosokawa;Tomoya Kinugawa;Hashmi Arqum;Hashmi Arqum
• 通讯作者: Hashmi Arqum

Valley selective excitations in WSe2 monolayer by (ω+2ω) pulses

(ω+2ω) 脉冲对 WSe2 单层的谷选择性激发

• 发表时间: 2022
• 作者: Takanobu Kirihara;Hajime Susa;Takashi Hosokawa;Tomoya Kinugawa;Hashmi Arqum;Hashmi Arqum;Hashmi Arqum;Hashmi Arqum
• 通讯作者: Hashmi Arqum

Sub-cycle control of valley polarization in WSe2 monolayer

WSe2单层谷极化的子循环控制

• 发表时间: 2022
• 作者: Takanobu Kirihara;Hajime Susa;Takashi Hosokawa;Tomoya Kinugawa;Hashmi Arqum;Hashmi Arqum;Hashmi Arqum
• 通讯作者: Hashmi Arqum

Valley polarization in WSe2 monolayer: CEP control of ω and ω+2ω Pulses

WSe2 单层中的谷极化：ω 和 ω+2ω 脉冲的 CEP 控制

• 发表时间: 2022
• 作者: Takanobu Kirihara;Hajime Susa;Takashi Hosokawa;Tomoya Kinugawa;Hashmi Arqum;Hashmi Arqum;Hashmi Arqum;Hashmi Arqum;Hashmi Arqum
• 通讯作者: Hashmi Arqum