Evidence of optical Aharonov-Bohm interference in spin-polarized moiré excitonic complexes

Quantum interference arising from the Aharonov-Bohm (AB) effect underlies a wide range of mesoscopic phenomena. Its optical analogue, in which excitonic dipoles acquire a magnetic-field-dependent phase while confined in nanoscale cavities, has been predicted but not yet observed in moiré materials. Here, we provide evidence for the optical Aharonov-Bohm effect (OAB) in twisted bilayer MoS2 aligned near 60∘. Magneto-photoluminescence experiments reveal periodic intensity oscillations of excitons and biexcitons, whose frequencies scale partially as integer multiples of an effective interference area, close to a fraction of the moiré unit cell. The biexcitons further exhibit valley-spin polarization reaching nearly 100% under moderate fields. Additionally, numerical simulations of the Wannier equation support the experimental observations, thus providing microscopic insight into the mechanism of the optical Aharonov-Bohm effect. These results provide evidence for phase-coherent excitonic interference in a solid state platform, which paves the way for moiré-based quantum emitters, valley-spin devices, and quantum information technologies. Here, the authors observe magneto-photoluminescence intensity oscillations in exciton and biexciton peaks of twisted bilayer MoS2, interpreted as optical Aharonov-Bohm interference with harmonic frequency hierarchy linked to the moiré-cell area.