@article{oai:kumadai.repo.nii.ac.jp:00021725,
 author = {黒田, 規敬 and 仁科, 雄一郎 and Nishina, Yuichiro and Kuroda, Noritaka and 仁科, 雄一郎 and Nishina, Yuichiro},
 issue = {2},
 journal = {Physical Review B},
 month = {Jan},
 note = {application/pdf, 論文(Article), The frequency separation between the essentially degenerate in-plane TO mode and its Davydov conjugate has been observed in the layer compound GaS in a measurement of the Raman and far-infrared spectra. The relative magnitude of the frequencies of the two modes is contrary to what is expected from interlayer Van der Waals forces. Wieting and Verble have observed a similar frequency reversal in the Davydov conjugates in the spectra of MoS2 and β-GaSe. They have argued that the long-range Coulomb interaction could be responsible for this optical anomaly. Our calculation shows, however, that the effect of such interaction in the deformation-dipole model approximation can not explain the anomaly., 層状半導体GaSにおける面内格子振動の横波光学(TO)モードとそのダビドフ共役モードのエネルギー差に注目してラマン散乱と遠赤外吸収を測定した。結果は層間のファンデルワールス力に基づいた予想と逆であった。同様の逆転現象がGaSeでもWietingとVerbleによって報告されているが、彼らが指摘した長距離クーロン力を考慮に入れても理論的に説明できない。それに代わる要因として、本論文では層状化合物の特殊性を考察して積層欠陥の役割を提案した。, http://link.aps.org/abstract/PRB/v19/p1312},
 pages = {1312--1315},
 title = {Davydov splitting of degenerate lattice modes in layer compound GaS},
 volume = {19},
 year = {1979},
 yomi = {ニシナ, ユウイチロウ and ニシナ, ユウイチロウ}
}