Abstract
Tungsten-based monolayer transition metal dichalcogenides host a long-lived “dark” exciton, an electron-hole pair in a spin-triplet configuration. The long lifetime and unique spin properties of the dark exciton provide exciting opportunities to explore light-matter interactions beyond electric dipole transitions. Here we demonstrate that the coupling of the dark exciton and an optically silent chiral phonon enables the intrinsic photoluminescence of the dark-exciton replica in monolayer WSe2. Gate and magnetic-field dependent PL measurements unveil a circularly-polarized replica peak located below the dark exciton by 21.6 meV, equal to E″ phonon energy from Se vibrations. First-principles calculations show that the exciton-phonon interaction selectively couples the spin-forbidden dark exciton to the intravalley spin-allowed bright exciton, permitting the simultaneous emission of a chiral phonon and a circularly-polarized photon. Our discovery and understanding of the phonon replica reveals a chirality dictated emission channel of the phonons and photons, unveiling a new route of manipulating valley-spin.
| Original language | English (US) |
|---|---|
| Article number | 2469 |
| Journal | Nature communications |
| Volume | 10 |
| Issue number | 1 |
| DOIs | |
| State | Published - Dec 1 2019 |
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ASJC Scopus subject areas
- Chemistry(all)
- Biochemistry, Genetics and Molecular Biology(all)
- Physics and Astronomy(all)
Cite this
Emerging photoluminescence from the dark-exciton phonon replica in monolayer WSe2. / Li, Zhipeng; Wang, Tianmeng; Jin, Chenhao; Lu, Zhengguang; Lian, Zhen; Meng, Yuze; Blei, Mark; Gao, Shiyuan; Taniguchi, Takashi; Watanabe, Kenji; Ren, Tianhui; Tongay, Sefaattin; Yang, Li; Smirnov, Dmitry; Cao, Ting; Shi, Su Fei.
In: Nature communications, Vol. 10, No. 1, 2469, 01.12.2019.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Emerging photoluminescence from the dark-exciton phonon replica in monolayer WSe2
AU - Li, Zhipeng
AU - Wang, Tianmeng
AU - Jin, Chenhao
AU - Lu, Zhengguang
AU - Lian, Zhen
AU - Meng, Yuze
AU - Blei, Mark
AU - Gao, Shiyuan
AU - Taniguchi, Takashi
AU - Watanabe, Kenji
AU - Ren, Tianhui
AU - Tongay, Sefaattin
AU - Yang, Li
AU - Smirnov, Dmitry
AU - Cao, Ting
AU - Shi, Su Fei
PY - 2019/12/1
Y1 - 2019/12/1
N2 - Tungsten-based monolayer transition metal dichalcogenides host a long-lived “dark” exciton, an electron-hole pair in a spin-triplet configuration. The long lifetime and unique spin properties of the dark exciton provide exciting opportunities to explore light-matter interactions beyond electric dipole transitions. Here we demonstrate that the coupling of the dark exciton and an optically silent chiral phonon enables the intrinsic photoluminescence of the dark-exciton replica in monolayer WSe2. Gate and magnetic-field dependent PL measurements unveil a circularly-polarized replica peak located below the dark exciton by 21.6 meV, equal to E″ phonon energy from Se vibrations. First-principles calculations show that the exciton-phonon interaction selectively couples the spin-forbidden dark exciton to the intravalley spin-allowed bright exciton, permitting the simultaneous emission of a chiral phonon and a circularly-polarized photon. Our discovery and understanding of the phonon replica reveals a chirality dictated emission channel of the phonons and photons, unveiling a new route of manipulating valley-spin.
AB - Tungsten-based monolayer transition metal dichalcogenides host a long-lived “dark” exciton, an electron-hole pair in a spin-triplet configuration. The long lifetime and unique spin properties of the dark exciton provide exciting opportunities to explore light-matter interactions beyond electric dipole transitions. Here we demonstrate that the coupling of the dark exciton and an optically silent chiral phonon enables the intrinsic photoluminescence of the dark-exciton replica in monolayer WSe2. Gate and magnetic-field dependent PL measurements unveil a circularly-polarized replica peak located below the dark exciton by 21.6 meV, equal to E″ phonon energy from Se vibrations. First-principles calculations show that the exciton-phonon interaction selectively couples the spin-forbidden dark exciton to the intravalley spin-allowed bright exciton, permitting the simultaneous emission of a chiral phonon and a circularly-polarized photon. Our discovery and understanding of the phonon replica reveals a chirality dictated emission channel of the phonons and photons, unveiling a new route of manipulating valley-spin.
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UR - http://www.scopus.com/inward/citedby.url?scp=85066936522&partnerID=8YFLogxK
U2 - 10.1038/s41467-019-10477-6
DO - 10.1038/s41467-019-10477-6
M3 - Article
VL - 10
JO - Nature Communications
JF - Nature Communications
SN - 2041-1723
IS - 1
M1 - 2469
ER -