Long lifetime of the E1u in-plane infrared-active modes of h-BN

This work has been supported by the Spanish MINECO/FEDER under Contracts No. MAT2015-71035-R and No. MAT2016-75586-C4-1-P. K.W. and T.T. acknowledge support from the Elemental Strategy Initiative conducted by the MEXT, Japan, Grant No. JPMXP0112101001, JPS, KAKENHI Grant No. JP20H00354, and the CREST (JPMJCR15F3), JST.