Transient Hydrodynamic Lattice Cooling by Picosecond Laser Irradiation of Graphite
Transient Hydrodynamic Lattice Cooling by Picosecond Laser Irradiation of Graphite
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DOI：
10.1103/physrevlett.127.085901
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发表时间：
2021-08-20
影响因子：
8.6
通讯作者：
Wang, Yaguo
中科院分区：
文献类型：
--
作者：
Jeong, Jihoon;Li, Xun;Wang, Yaguo
最近的理论和实验表明，在异常高温下石墨中的流体动力学声子输运特性。在这里，我们报告了一个皮秒泵浦探测热反射测量热脉冲在石墨中的传播。测量结果表明，在80 ~ 120 K温度范围内，15 μ m直径环形泵浦光束的绝热中心附近存在瞬态晶格冷却。虽然这种晶格冷却还没有报道在最近的衍射测量石墨中的第二个声音，这里的观察是一致的流体动力学声子输运理论和之前的热脉冲测量散装氟化钠中的第二个声音。
Recent theories and experiments have suggested hydrodynamic phonon transport features in graphite at unusually high temperatures. Here, we report a picosecond pump-probe thermal reflectance measurement of heat-pulse propagation in graphite. The measurement results reveal transient lattice cooling near the adiabatic center of a 15-mu m-diameter ring-shape pump beam at temperatures between 80 and 120 K. While such lattice cooling has not been reported in recent diffraction measurements of second sound in graphite, the observation here is consistent with both hydrodynamic phonon transport theory and prior heat-pulse measurements of second sound in bulk sodium fluoride.