TY - JOUR
T1 - Every-other-layer dipolar excitons in a spin-valley locked superlattice
AU - Zhang, Yinong
AU - Xiao, Chengxin
AU - Ovchinnikov, Dmitry
AU - Zhu, Jiayi
AU - Wang, Xi
AU - Taniguchi, Takashi
AU - Watanabe, Kenji
AU - Yan, Jiaqiang
AU - Yao, Wang
AU - Xu, Xiaodong
N1 - Publisher Copyright:
© 2023, The Author(s), under exclusive licence to Springer Nature Limited.
PY - 2023/5
Y1 - 2023/5
N2 - Monolayer semiconducting transition metal dichalcogenides possess broken inversion symmetry and strong spin-orbit coupling, leading to a unique spin-valley locking effect. In 2H stacked pristine multilayers, spin-valley locking yields an electronic superlattice structure, where alternating layers correspond to barriers and quantum wells depending on the spin-valley indices. Here we show that the spin-valley locked superlattice hosts a kind of dipolar exciton with the electron and hole constituents separated in an every-other-layer configuration: that is, either in two even or two odd layers. Such excitons become optically bright via hybridization with intralayer excitons. This effect is also manifested by the presence of multiple anti-crossing patterns in the reflectance spectra, as the dipolar exciton is tuned through the intralayer resonance by an electric field. The reflectance spectra further reveal an excited state orbital of the every-other-layer exciton, pointing to a sizable binding energy in the same order of magnitude as the intralayer exciton. As layer thickness increases, the dipolar exciton can form a one-dimensional Bose–Hubbard chain displaying layer number-dependent fine spectroscopy structures.
AB - Monolayer semiconducting transition metal dichalcogenides possess broken inversion symmetry and strong spin-orbit coupling, leading to a unique spin-valley locking effect. In 2H stacked pristine multilayers, spin-valley locking yields an electronic superlattice structure, where alternating layers correspond to barriers and quantum wells depending on the spin-valley indices. Here we show that the spin-valley locked superlattice hosts a kind of dipolar exciton with the electron and hole constituents separated in an every-other-layer configuration: that is, either in two even or two odd layers. Such excitons become optically bright via hybridization with intralayer excitons. This effect is also manifested by the presence of multiple anti-crossing patterns in the reflectance spectra, as the dipolar exciton is tuned through the intralayer resonance by an electric field. The reflectance spectra further reveal an excited state orbital of the every-other-layer exciton, pointing to a sizable binding energy in the same order of magnitude as the intralayer exciton. As layer thickness increases, the dipolar exciton can form a one-dimensional Bose–Hubbard chain displaying layer number-dependent fine spectroscopy structures.
UR - http://www.scopus.com/inward/record.url?scp=85150630158&partnerID=8YFLogxK
U2 - 10.1038/s41565-023-01350-1
DO - 10.1038/s41565-023-01350-1
M3 - Article
C2 - 36959300
AN - SCOPUS:85150630158
SN - 1748-3387
VL - 18
SP - 501
EP - 506
JO - Nature Nanotechnology
JF - Nature Nanotechnology
IS - 5
ER -