Abstract
We investigated the coherent acoustic and optical phonon dynamics in a Ge2Sb2Te5 phase change material by using pump-probe spectroscopy. Oscillating reflectivity changes with oscillation period and de-phasing time on a timescale of tens of picoseconds were observed and could be consistently explained by coherent acoustic phonon generation in the form of a strain pulse propagating into substrate. The temperature-dependent frequency shift of the coherent optical A 1 phonon mode was due to a three-phonon anharmonic decay while its de-phasing was dominated by temperatureindependent phonon-vacancy scattering at low temperature. A laser-fluence-dependent A 1 phonon mode softening and a dephasing rate increase were observed and attributed to the high density of electrons and the accompanying lattice distortion, as well as the increase in the lattice temperature.
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N. Yamada, E. Ohno, K. Nishiuchi and N. Akahira, J. Appl. Phys. 69, 2849 (1991).
N. Yamada and T. Matsunaga, J. Appl. Phys. 88, 7020 (2000).
T. Nonaka, G. Ohbayashi, Y. Toriumi, Y. Mori and H. Hashimoto, Thin Solid Films 370, 258 (2000).
A. V. Kolobov, P. Fons, A. I. Frenkel, A. L. Ankudinov, J. Tominaga and T. Uruga, Nature Mater. 3, 703 (2004).
A. V. Kolobov, J. Haines, A. Pradel, M. Ribes, P. Fons, J. Tominaga, Y. Katayama, T. Hammouda and T. Uruga, Phys. Rev. Lett. 97, 035701 (2006).
D. A. Baker, M. A. Paesler, G. Lucovsky, S. C. Agarwal and P. C. Taylor, Phys. Rev. Lett. 96, 255501 (2006).
P. Fons, H. Osawa, A. V. Kolobov, T. Fukaya, M. Suzuki, T. Uruga, N. Kawamura, H. Tanida and J. Tominaga, Phys. Rev. B. 82, 041203(R) (2010).
M. Konishi, H. Santo, Y. Hongo, K. Tajima, M. Hosoi and T. Saiki, Appl. Optics 49, 3470 (2010).
K. Makino, J. Tominaga and M. Hase, Optical Express 19, 1260 (2011).
M. Hase, M. Kitajima, S. I. Nakashima and K. Mizoguchi, Phys. Rev. Lett. 88, 067401 (2002).
A. Cavalleri, Th. Dekorsy, H. H. W. Chong, J. C. Kieffer and R. W. Schoenlein, Phys. Rev. B 70, 161102(R) (2004).
C. Kübler, H. Ehrke, R. Huber, R. Lopez, A. Halabica, R. F. Haglund Jr. and A. Leitenstorfer,, Phys. Rev. Lett. 99,116401 (2007).
J. Hernandez-Rueda, A. Savoia, W. Gawelda, J. Solis, B. Mansart, D. Boschetto and J. Siegel, Appl. Phys. Lett. 98, 251906 (2011).
A. Yamamoto, T. Mishina and Y. Yasumoto, Phys. Rev. Lett. 73, 740 (1994).
A. Bartels, T. Dekorsky, H. Kurds and K. Kohler, Phys. Rev. Lett. 82, 1044 (1999).
C. Sun, J. Liang and X. Yu, Phys. Rev. Lett. 84, 179 (1999).
C. Thomsen, J. Strait, Z. Vardeny, H. J. Maris, J. Tauc and J. J. Hauser, Phys. Rev. Lett. 53, 989 (1984).
C. Thomsen, H. Grahn, H. J. Maris and J. Tauc, Phys. Rev. B 34, 4129 (1986).
J.-W. Park, S. Ho Baek, T. D. Kang, H. Lee and Y.-S. Kang, Appl. Phys. Lett. 93, 021914 (2008).
H.-K. Lyeo, D. G. Cahill, B.-S. Lee and John R. Abelson, Appl. Phys. Lett. 89, 151904 (2006).
M. Först, T. Dekorsy, C. Trappe, M. Laurenzis and H. Kurz,, Appl. Phys. Lett. 77, 1964 (2000).
S. Anand, P. Verma, K. P. Jain and S. C. Abbi, Physica 226, 331 (1996).
S. Hunsche, K. Wienecke, T. Dekorsy and H. Kurz, Phys. Rev. Lett. 75, 1815 (1995).
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Kim, D.H., Park, J.W., Lee, H. et al. Ultrafast coherent phonon dynamics in Ge2Sb2Te5 thin films. Journal of the Korean Physical Society 62, 743–748 (2013). https://doi.org/10.3938/jkps.62.743
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DOI: https://doi.org/10.3938/jkps.62.743