Dynamics of optical phonons in Bi2Se3 crystal studied using femtosecond time-resolved reflection measurementKatsura Norimatsu, Jianbo Hu, Arihiro Goto, Kyushiro Igarashi, Takao Sasagawa and Kazutaka G. NakamuraEPJ Web of Conferences, 41 (2013) 03008DOI: https://doi.org/10.1051/epjconf/20134103008