[17a-A35-1~9] 4.5 Nanocarbon and 2D Materials

11:15 〜 11:30英語発表

[17a-A35-7] Identification and manipulation of valley coherence in monolayer WSe₂

〇(D)Wang Haonan¹, Kenji Watanabe², Takashi Taniguchi², Kazunari Matsuda¹ (1.IAE, Kyoto Univ., 2.NIMS)

キーワード：

monolayer WSe2、valley coherence、interferometry

The monolayer transition metal dichalcogenide (TMDs) are granted with valley degree of freedom due to broken inversion symmetry, and strong spin-orbit coupling. The degenerated states at band-edges of K(K^’) valley possess information of valley pseudospin, which experiences intervalley decoherence process during emission. With valley decoherence not coupling to any radiative dipole, direct probing or manipulation of valley coherence in the time domain has remain a challenge. Here we propose a method of optically exploring the valley coherence time in the time-domain measurement. Furthermore, the valley coherence of monolayer (1L) WSe₂ device under various carrier densities are also explored in the spectral and time domain.