Mode-selective excitation of coherent surface phonons on alkali-covered metal surfaces.
We demonstrate the mode-selective excitation of coherent phonons at Pt(111) surfaces covered with submonolayer caesium atoms. A burst of 150 fs laser pulses with the repetition rate of 2.0-2.9 THz was synthesized by using a spatial-light modulator, and used for the coherent surface phonon excitation. The coherent nuclear motion was monitored by time-resolved second harmonic generation. By tuning the repetition rate, we succeeded in controlling the relative amplitude of the vibrational coherence of the Cs-Pt stretching mode (2.3-2.4 THz) to that of the Pt surface Rayleigh phonon mode (2.6 or 2.9 THz, depending on the Cs coverage).
Watanabe
Kazuya
K
National Institutes of Natural Sciences, Institute for Molecular Science, Okazaki, Aichi 444-8585, Japan.
Takagi
Noriaki
N
Matsumoto
Yoshiyasu
Y
D002586:Cesium / Q000737:chemistry*; D007700:Kinetics; D008672:Metals, Alkali / Q000737:chemistry*; D010984:Platinum / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared; D013499:Surface Properties; D014732:Vibration
D008672:Metals, Alkali; D002586:Cesium; D010984:Platinum