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Tuning layer-hybridized moiré excitons by the quantum-confined Stark effect

Cornell Affiliated Author(s)

Author

Y. Tang
J. Gu
S. Liu
K. Watanabe
T. Taniguchi
J. Hone
K.F. Mak
J. Shan

Abstract

Moiré superlattices offer an unprecedented opportunity for tailoring interactions between quantum particles1–11 and their coupling to electromagnetic fields12–18. Strong superlattice potentials generate moiré minibands of excitons16–18—bound pairs of electrons and holes that reside either in a single layer (intralayer excitons) or in two separate layers (interlayer excitons). Twist-angle-controlled interlayer electronic hybridization can also mix these two types of exciton to combine their strengths13,19,20. Here we report the direct observation of layer-hybridized moiré excitons in angle-aligned WSe2/WS2 and MoSe2/WS2 superlattices by optical reflectance spectroscopy. These excitons manifest a hallmark signature of strong coupling in WSe2/WS2, that is, energy-level anticrossing and oscillator strength redistribution under a vertical electric field. They also exhibit doping-dependent renormalization and hybridization that are sensitive to the electronic correlation effects. Our findings have important implications for emerging many-body states in two-dimensional semiconductors, such as exciton condensates21 and Bose–Hubbard models22, and optoelectronic applications of these materials. © 2020, The Author(s), under exclusive licence to Springer Nature Limited.

Date Published

Journal

Nature Nanotechnology

Volume

16

Issue

1

Number of Pages

52-57,

URL

https://www.scopus.com/inward/record.uri?eid=2-s2.0-85094955451&doi=10.1038%2fs41565-020-00783-2&partnerID=40&md5=419642327786d25b34058e79af959199

DOI

10.1038/s41565-020-00783-2

Group (Lab)

Jie Shan Group
Kin Fai Mak Group

Funding Source

FA9550-18-1-0480
DMR-2004451
W911NF-17-1-0605
DE-SC0019481
JPMJCR15F3

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