POEM

Artificial atoms in quantum materials are central to quantum light sources. POEM explores a new way to generate on-demand, correlated quantum light from excitons trapped in the moiré lattice of two-dimensional transition-metal dichalcogenide heterobilayers.

In a WSe₂/MoSe₂ heterobilayer, the electron and the hole of an interlayer exciton sit in different layers. Their large binding energy, long lifetime and strong electric dipole make them highly tunable, and the moiré potential traps them into arrays of single-photon emitters. Because of their chiral optical selection rules, the circular polarisation of the emitted photon can be tied to the direction in which it leaves the sample.

POEM aims to demonstrate polarisation-path correlated single photons from moiré-trapped interlayer excitons, combining electrical control of carrier doping with a dichromatic excitation scheme: two synchronised laser fields that selectively address the valley degree of freedom on ultrafast timescales. The emitted states will be characterised by quantum-state tomography, with prospects for single-photon switching, quantum sensing and quantum communications.