Interlayer dark excitons in a van der Waals heterostructure

@misc{ma2026interlayer,
  title = {{Interlayer dark excitons in a van der Waals heterostructure}},
  author = {Rundong Ma and Konstantin Davydov and Liuxin Gu and Lifu Zhang and Hassan Alnatah and Beini Gao and Ruihao Ni and Suji Park and Houk Jang and Takashi Taniguchi and Kenji Watanabe and You Zhou},
  howpublished = {arXiv},
  year = {2026},
  month = sep,
  doi = {10.48550/arxiv.2609.38033},
  eprint = {2609.38033},
  archivePrefix = {arXiv},
  url = {https://arxiv.org/abs/2609.38033},
}

TY  - UNPB
TI  - Interlayer dark excitons in a van der Waals heterostructure
AU  - Rundong Ma
AU  - Konstantin Davydov
AU  - Liuxin Gu
AU  - Lifu Zhang
AU  - Hassan Alnatah
AU  - Beini Gao
AU  - Ruihao Ni
AU  - Suji Park
AU  - Houk Jang
AU  - Takashi Taniguchi
AU  - Kenji Watanabe
AU  - You Zhou
PY  - 2026
DA  - 2026/09/29
PB  - arXiv
DO  - 10.48550/arxiv.2609.38033
UR  - https://arxiv.org/abs/2609.38033
AB  - Interlayer excitons in transition metal dichalcogenide (TMD) heterostructures exhibit long lifetimes and long-range transport, making them promising for excitonic devices and quantum many-body phases, such as Bose-Einstein condensates. Achieving these goals requires a precise understanding of spin-allowed bright and nominally spin-forbidden dark excitons, because the lowest-energy exciton species governs population, transport, and condensation. Despite substantial progress, unambiguously distinguishing singlet and triplet interlayer excitons has been challenging, as moiré excitons in these heterostructures can mimic their optical signatures. Here, we report the direct spectroscopic identification of bright (singlet) and dark (triplet) interlayer excitons in high-quality, dual-gated WSe_2/hBN/WSe_2 homobilayers. Electric-field-dependent photoluminescence and reflectance reveal two momentum-direct interlayer transitions with distinct spin configurations. The interlayer dark excitons obey selection rules that differ from those of bright excitons. Strikingly, interlayer dark excitons retain strong valley polarization, even with their ultralong lifetime exceeding microseconds. Finally, we demonstrate twist-angle control, wherein twist-induced electron-hole momentum mismatch modulates interlayer exciton emission. These results provide critical insights into the electronic and excitonic structure of TMD heterostructures, opening new avenues for excitonic many-body physics and optoelectronic devices.
ER  -