講演情報
[7a-P05-71]Doping-dependent valley polarization induced by Mott transition in WSe2/WS2 moiré superlattice
〇(D)Li Zhiwei1, Kazunari Matsuda1, Takashi Taniguchi2, Kenji Watanabe2 (1.Kyoto Univ., 2.NIMS)
キーワード：
heterostructure、2D materials
Monolayer MX2 (M = Mo, W; X = S, Se) heterobilayers with slight lattice mismatch form moiré superlattices that confine excitons in flat minibands described by a Hubbard model. In WSe2/WS2, strong electron correlations induce a Mott transition that modulates valley polarization of interlayer excitons. We observe a 10 meV blueshift at n = 1 and a DOCP increase from 15 % to 50 % via polarization- and time-resolved PL. Remarkably, valley splitting persists at n = 1 without an external magnetic field, as additional electrons occupy both −K and Q valleys, breaking valley symmetry. These results establish WSe2/WS2 moiré heterostructures as platforms for tunable valleytronic devices.