光诱导的非热相过渡到SnSe中的拓晶体绝缘体状态
Stefano Mocatti1, Giovanni Marini1, Matteo Calandra1
1Department of Physics, University of Trento, Via Sommarive 14, 38123 Povo, Italy.
The journal of physical chemistry letters
|October 11, 2023
概括
超快的激光器可以永久地将锡化物 (SnSe) 从微不足道转化为拓晶体绝缘相. 这种光诱导相位过渡是一种罕见的非热过程,为材料工程提供了新的可能性.
科学领域:
- 凝聚物质物理学 凝聚物质物理学
- 材料科学 材料科学 材料科学
- 量子力学就是量子力学.
背景情况:
- 五秒激光脉冲可以诱导短暂的转移稳定状态,但永久的光诱导相位过渡与改变的拓顺序是罕见的.
- 实现稳定,光诱导的拓相位过渡需要精确控制和理解光物质相互作用.
研究的目的:
- 研究超快激光器在锡化物 (SnSe) 中诱导永久的非热相变的潜力.
- 探索从一个拓上微不足道的形结构到一个拓的晶体绝缘 (TCI) 岩盐阶段的转变.
- 为了阐明这种光诱导过渡的反应途径,关键激光流量和衰变通道.
主要方法:
- 利用受约束密度功能扰动理论 (DFPT) 来建模光诱导相位过渡.
- 在理论框架中纳入光诱导的量子无和性.
- 模拟光激发结构和振动特性,以与实验数据进行比较.
主要成果:
- 证明超快激光器可以通过一级非热过渡永久地将形SnSe结构转化为TCI岩盐阶段.
- 描述了反应路径,并确定了过渡所需的关键激光流量.
- 模拟的特性与最近的探头实验数据显示出很好的一致性 (量子自由能量曲率<2%的误差).
结论:
- 超快激光激发提供了一条可行的途径,在像SnSe.Se这样的材料中实现永久的,非热拓相位过渡.
- 这些发现为工程拓材料提供了一条新的途径,在先进电子和自旋电子学中具有潜在的应用.
- 理论建模准确地预测和解释了光诱导结构和拓变化的实验观测.
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