TY - JOUR
T1 - Moiré-Trapped Interlayer Trions in a Charge-Tunable WSe2/MoSe2 Heterobilayer
AU - Brotons-Gisbert, Mauro
AU - Baek, Hyeonjun
AU - Campbell, Aidan
AU - Watanabe, Kenji
AU - Taniguchi, Takashi
AU - Gerardot, Brian D.
N1 - Funding Information:
We thank Mikhail M. Glazov for fruitful discussions. This work is supported by the EPSRC (Grants No. EP/P029892/1 and No. EP/L015110/1), the ERC (Grant No. 725920), and the EU Horizon 2020 research and innovation program under Grant Agreement No. 820423. Growth of -BN crystals by K. W. and T. T. is supported by the Elemental Strategy Initiative conducted by the MEXT, Japan, Grant No. JPMXP0112101001, JSPS KAKENHI Grant No. JP20H00354, and the CREST (Grant No. JPMJCR15F3), JST. B. D. G. is supported by a Wolfson Merit grant from the Royal Society and a Chair in Emerging Technology from the Royal Academy of Engineering.
Publisher Copyright:
© 2021 authors. Published by the American Physical Society.
PY - 2021/9
Y1 - 2021/9
N2 - Transition-metal dichalcogenide heterobilayers offer attractive opportunities to realize lattices of interacting bosons with several degrees of freedom. Such heterobilayers can feature moiré patterns that modulate their electronic band structure, leading to spatial confinement of single interlayer excitons (IXs) that act as quantum emitters with C3 symmetry. However, the narrow emission linewidths of the quantum emitters contrast with a broad ensemble IX emission observed in nominally identical heterobilayers, opening a debate regarding the origin of IX emission. Here we report the continuous evolution from a few trapped IXs to an ensemble of IXs with both triplet- and singlet-spin configurations in a gate-tunable 2H-MoSe2/WSe2 heterobilayer. We observe signatures of dipolar interactions in the IX ensemble regime which, when combined with magneto-optical spectroscopy, reveal that the narrow quantum-dot-like and broad ensemble emission originate from IXs trapped in moiré potentials with the same atomic registry. Finally, electron doping leads to the formation of three different species of localized negative trions with contrasting spin-valley configurations, among which we observe both intervalley and intravalley IX trions with spin-triplet optical transitions. Our results identify the origin of IX emission in MoSe2/WSe2 heterobilayers and highlight the important role of exciton-exciton interactions and Fermi-level control in these highly tunable quantum materials.
AB - Transition-metal dichalcogenide heterobilayers offer attractive opportunities to realize lattices of interacting bosons with several degrees of freedom. Such heterobilayers can feature moiré patterns that modulate their electronic band structure, leading to spatial confinement of single interlayer excitons (IXs) that act as quantum emitters with C3 symmetry. However, the narrow emission linewidths of the quantum emitters contrast with a broad ensemble IX emission observed in nominally identical heterobilayers, opening a debate regarding the origin of IX emission. Here we report the continuous evolution from a few trapped IXs to an ensemble of IXs with both triplet- and singlet-spin configurations in a gate-tunable 2H-MoSe2/WSe2 heterobilayer. We observe signatures of dipolar interactions in the IX ensemble regime which, when combined with magneto-optical spectroscopy, reveal that the narrow quantum-dot-like and broad ensemble emission originate from IXs trapped in moiré potentials with the same atomic registry. Finally, electron doping leads to the formation of three different species of localized negative trions with contrasting spin-valley configurations, among which we observe both intervalley and intravalley IX trions with spin-triplet optical transitions. Our results identify the origin of IX emission in MoSe2/WSe2 heterobilayers and highlight the important role of exciton-exciton interactions and Fermi-level control in these highly tunable quantum materials.
UR - http://www.scopus.com/inward/record.url?scp=85113184134&partnerID=8YFLogxK
U2 - 10.1103/PhysRevX.11.031033
DO - 10.1103/PhysRevX.11.031033
M3 - Article
AN - SCOPUS:85113184134
SN - 2160-3308
VL - 11
JO - Physical Review X
JF - Physical Review X
IS - 3
M1 - 031033
ER -