Observation of Quasisteady Dark Excitons and Gapped State in a Doped Semiconductor

Physical Review Letters 2026 Open access

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Authors: Shangkun Mo, Yunfei Bai, Chunlong Wu, Xingxia Cui, Guangqiang Mei, Qiang Wan, Renzhe Li, Cheng Peng, Keming Zhao, Dingkun Qin, Shuming Yu, Hao Zhong
+7 more Xin Wang, Enting Li, Yiwei Li, Limin Cao, Min Feng, Sheng Meng, Nan Xu
DOI: 10.1103/x1bq-wgb3
Cited by: 2
References: 62

Abstract

Excitons underpin optical phenomena and can intertwine with correlated electronic states. Unlike bright excitons, dark excitons evade conventional optical detection, and their impact on quasiequilibrium electronic structures remains largely unexplored. Here, using angle-resolved photoemission spectroscopy, we report creating, detecting, and controlling dark excitons in the quasiequilibrium distribution of a doped semiconductor SnSe_{2}. By tuning doping and temperature, we control the excitonic spectral weight and observe a concomitant anisotropic gapped state. Our results broaden the scope of dark excitons beyond ultrafast photoemission studies and highlight a correlation between dark excitons and correlated electrons under quasiequilibrium conditions.

Fields of Study & Subjects

Semiconductor Quantum Structures and Devices Strong Light-Matter Interactions Quantum optics and atomic interactions

Publication details

Journal / source
Physical Review Letters
Publisher
American Physical Society (APS)
Volume
136
Issue
10
Pages
106401–106401
Publication date
6 February 2026
Language
EN