Zhe Sun, Mohamed Shehabeldin, Jian Tang, Mingyang Guo, Zumeng Huang, Tianxing Tang, Tiema Qian, Vsevolod Belosevich, Thomas Siyuan Ding, Jingdi Tang, Yangchen He, Ivona Košić, Michael Geiwitz, Kenji Watanabe, Takashi Taniguchi, Kenneth Stephen Burch, Efrén Navarro-Moratalla, Daniel Rhodes, Chun Hung Lui, Ni Ni, Su-Yang Xu, Qiong Ma
A tunable interface between flying photons and stationary quantum states is important for quantum networks. Quantum-confined charged excitons are attractive in this context because they combine single-photon emission with localized charge states. However, realizing nanoscale electrostatic confinement that is reversible, robust and spectroscopically resolvable remains challenging. Here we show luminous, quantum-confined charged excitons in monolayer WSe2 using an electrostatic quantum nanocorral. A quantum corral was first realized using scanning tunnelling microscopy, where individual adatoms are arranged in a ring on a metal surface to confine electronic standing waves. In our approach, monolayer WSe2 is gated through a nanoporous metallic monolayer less than 1-nm thick, which acts as an electric-field mask and defines confinement on ~10-nm length scales. This geometry creates distinct excitonic quasiparticle states inside and outside the nanopore, with ultrabright charged excitons confined by surrounding higher-energy neutral-exciton states. The resulting confinement produces pronounced energy splittings and clear spectroscopic signatures of discrete centre-of-mass modes. The electrostatic barrier is dynamically reconfigurable, allowing a crossover between zero- and two-dimensional excitonic states, while polarization-resolved measurements reveal signatures of fine-structure splitting. These results establish an electrically tunable route to controlling charged excitons for quantum light sources with adjustable brightness, energy and photon statistics.