Non-equilibrium dynamics of the phonon system (B04)

声子系统的非平衡动力学（B04）

• 批准号: 317675875
• 金额: --
• 依托单位: Dekanat Fakultät für Physik
• 依托单位国家: 德国
• 项目类别: Collaborative Research Centres
• 财政年份: 2016
• 资助国家: 德国
• 起止时间: 2015-12-31 至 2023-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/317675875?language=en
• 关键词: Non; equilibrium; dynamics; phonon; system

The excitation, decay, and transport of phonons in crystalline films and at their surfaces upon an optical excitation will be studied by ultrafast electron diffraction with femtosecond temporal resolution. We focus on the manipulation of electron phonon coupling through variation of electronic states, strain state, surface and interface roughness and thus control the vibrational excitation of lattice through either formation of squeezed state, e-ph coupling through surface state, or anharmonic ph-ph coupling. We force violation of equipartition in the phonon system through switching from diffusive to ballistic phonon transport.

我们将用飞秒时间分辨率的超快电子衍射来研究晶体薄膜及其表面声子在光激发下的激发、衰减和输运。我们重点研究了通过改变电子态、应变态、表面粗糙度和界面粗糙度来控制电子声子耦合，从而通过形成压缩态、通过表面态进行e-ph耦合或通过非谐ph-ph耦合来控制晶格的振动激发。我们通过从扩散声子输运到弹道声子输运的转换，迫使声子系统中的均分破坏。