Evidence for moire excitons in van der Waals heterostructures

被引：904

作者：

Kha Tran ^{[1
,2
]}

Moody, Galan ^{[3
]}

Wu, Fengcheng ^{[4
]}

Lu, Xiaobo ^{[5
]}

Choi, Junho ^{[1
,2
]}

Kim, Kyounghwan ^{[6
]}

Rai, Amritesh ^{[6
]}

Sanchez, Daniel A. ^{[7
]}

Quan, Jiamin ^{[1
,2
]}

Singh, Akshay ^{[1
,2
,12
]}

Embley, Jacob ^{[1
,2
]}

Zepeda, Andre ^{[1
,2
]}

Campbell, Marshall ^{[1
,2
]}

Autry, Travis ^{[3
]}

Taniguchi, Takashi ^{[8
]}

Watanabe, Kenji ^{[8
]}

Lu, Nanshu ^{[7
,9
]}

Banerjee, Sanjay K. ^{[6
]}

Silverman, Kevin L. ^{[3
]}

Kim, Suenne ^{[10
,11
]}

Tutuc, Emanuel ^{[6
]}

Yang, Li ^{[5
]}

MacDonald, Allan H. ^{[1
,2
]}

Li, Xiaoqin ^{[1
,2
,7
]}

机构：

[1] Univ Texas Austin, Dept Phys, Austin, TX 78712 USA

[2] Univ Texas Austin, Ctr Complex Quantum Syst, Austin, TX 78712 USA

[3] NIST, Boulder, CO USA

[4] Argonne Natl Lab, Div Mat Sci, 9700 S Cass Ave, Argonne, IL 60439 USA

[5] Washington Univ, Dept Phys, St Louis, MO 63130 USA

[6] Univ Texas Austin, Dept Elect & Comp Engn, Microelect Res Ctr, Austin, TX 78712 USA

[7] Univ Texas Austin, Texas Mat Inst, Austin, TX 78712 USA

[8] Natl Inst Mat Sci, Tsukuba, Ibaraki, Japan

[9] Univ Texas Austin, Dept Aerosp Engn & Engn Mech, Austin, TX 78712 USA

[10] Hanyang Univ, Dept Photon & Nanoelect, Ansan, South Korea

[11] Hanyang Univ, Dept Appl Phys, Ansan, South Korea

[12] MIT, Dept Mat Sci & Engn, Cambridge, MA 02139 USA

来源：

NATURE | 2019年 / 567卷 / 7746期

基金：

新加坡国家研究基金会; 美国国家科学基金会;

关键词：

VALLEY POLARIZATION; INTERLAYER EXCITONS; MOS2;

D O I：

10.1038/s41586-019-0975-z

中图分类号：

O [数理科学和化学]; P [天文学、地球科学]; Q [生物科学]; N [自然科学总论];

学科分类号：

07 ; 0710 ; 09 ;

摘要：

Recent advances in the isolation and stacking of monolayers of van der Waals materials have provided approaches for the preparation of quantum materials in the ultimate two-dimensional limit(1,2). In van der Waals heterostructures formed by stacking two monolayer semiconductors, lattice mismatch or rotational misalignment introduces an in-plane moire superlattice(3). It is widely recognized that the moire superlattice can modulate the electronic band structure of the material and lead to transport properties such as unconventional superconductivity(4) and insulating behaviour driven by correlations(5-7); however, the influence of the moire superlattice on optical properties has not been investigated experimentally. Here we report the observation of multiple interlayer exciton resonances with either positive or negative circularly polarized emission in a molybdenum diselenide/tungsten diselenide (MoSe2/WSe2) heterobilayer with a small twist angle. We attribute these resonances to excitonic ground and excited states confined within the moire potential. This interpretation is supported by recombination dynamics and by the dependence of these interlayer exciton resonances on twist angle and temperature. These results suggest the feasibility of engineering artificial excitonic crystals using van der Waals heterostructures for nanophotonics and quantum information applications.

引用

页码：71 / +

页数：13

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