Opto-Mechanics Driven Fast Martensitic Transition in Two-Dimensional Materials.
Opto-Mechanics Driven Fast Martensitic Transition in Two-Dimensional Materials.
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DOI：
10.1021/acs.nanolett.8b03559
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发表时间：
2018-11
期刊：
影响因子：
10.8
通讯作者：
Jian Zhou;Jian Zhou;Haowei Xu;Yifei Li;R. Jaramillo;Ju Li
中科院分区：
文献类型：
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作者：
Jian Zhou;Jian Zhou;Haowei Xu;Yifei Li;R. Jaramillo;Ju Li
扩散相变材料，如Ge-Sb-Te合金，用于可重写非易失性存储器件。但是，在小型化设备中不断追求读/写速度和降低能耗，要求在超薄材料中采用光学驱动、无扩散的相变方案。受光镊子的启发，我们从理论和计算上证明了选定频率的线偏振激光脉冲可以驱动SnO和SnSe单层等二维铁弹性材料的超快无扩散马氏体相变，其中晶胞应变被钳制为影响各向异性介电函数和电磁能量密度的广义坐标。当激光功率为2.0×1010W/cm2和7.7×109W/cm2时，SnO和SnSe的两个90°取向的铁弹性单层之间的跃迁势垒分别消失，因此可以在皮秒内发生位移域转换。这种光机械马氏体相变(OMT)的能量输入绝热极限估计至少比Ge-Sb-Te合金低2个数量级。
Diffusional phase-change materials, such as Ge-Sb-Te alloys, are used in rewritable nonvolatile memory devices. But the continuous pursuit of readout/write speed and reduced energy consumption in miniaturized devices calls for an optically driven, diffusionless phase change scheme in ultrathin materials. Inspired by optical tweezers, in this work, we illustrate theoretically and computationally that a linearly polarized laser pulse with selected frequency can drive an ultrafast diffusionless martensitic phase transition of two-dimensional ferroelastic materials such as SnO and SnSe monolayers, where the unit-cell strain is tweezed as a generalized coordinate that affects the anisotropic dielectric function and electromagnetic energy density. At laser power of 2.0 × 1010 and 7.7 × 109 W/cm2, the transition potential energy barrier vanishes between two 90°-orientation variants of ferroelastic SnO and SnSe monolayer, respectively, so displacive domain switching can occur within picoseconds. The estimated adiabatic thermal limit of energy input in such optomechanical martensitic transition (OMT) is at least 2 orders of magnitude lower than that in Ge-Sb-Te alloy.