Kozina M, van Driel T, Chollet M, Sato T, Glownia J M, Wandel S, Radovic M, Staub U, Hoffmann M C
Linac Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA.
Swiss Light Source, Paul Scherrer Institut, 5232 Villigen PSI, Switzerland.
Struct Dyn. 2017 May 3;4(5):054301. doi: 10.1063/1.4983153. eCollection 2017 Sep.
We use ultrafast X-ray pulses to characterize the lattice response of SrTiO when driven by strong terahertz fields. We observe transient changes in the diffraction intensity with a delayed onset with respect to the driving field. Fourier analysis reveals two frequency components corresponding to the two lowest energy zone-center optical modes in SrTiO. The lower frequency mode exhibits clear softening as the temperature is decreased while the higher frequency mode shows slight temperature dependence.
我们使用超快X射线脉冲来表征在强太赫兹场驱动下SrTiO的晶格响应。我们观察到衍射强度的瞬态变化相对于驱动场有延迟的起始。傅里叶分析揭示了对应于SrTiO中两个最低能量区中心光学模式的两个频率分量。较低频率模式随着温度降低表现出明显的软化，而较高频率模式显示出轻微的温度依赖性。
