Observation of hot-electron pressure in the vibration dynamics of metal nanoparticles
1Lehrstuhl fur Photonik und Optoelektronik, Sektion Physik and CeNS, Ludwig-Maximilians-Universitat Munchen, Amalienstrasse 54, D-80799 Munchen, Germany.
Physical Review Letters
|September 16, 2000
Abstract:
We investigate the vibration dynamics of ellipsoidal silver nanoparticles, using time-resolved optical pump-probe spectroscopy. When excited with femtosecond laser pulses, the particles execute anisotropic shape oscillations. We show that these vibrations are triggered by the thermal expansion of the optically heated particles. The time dependence of the vibrations indicates that this expansion is caused by two mechanisms: The lattice anharmonicity and the extremely large pressure of the hot conduction electrons.
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