Harnessing excitons at the nanoscale - photoelectrical sensing and quantification

Excitons, quasiparticles formed by the binding of an electron and a hole through electrostatic attraction, hold promise in the realms of quantum light confinement and optoelectronic sensing. Atomically thin transition metal dichalcogenides (TMDs) provide a highly versatile platform for hosting and manipulating excitons, given their robust Coulomb interactions and exceptional sensitivity to dielectric environment. In this talk, we introduce a photoelectrical sensing technique, termed optically coupled microwave impedance microscopy (OC-MIM). OC-MIM enables the sensitive probing of exciton polarons and their Rydberg states at the nanoscale, unveiling their potential as localized quantum sensors. By utilizing this technique, we explore the interplay between excitons and material properties at the nanoscale, including carrier density, in-plane electric field, and dielectric screening. Furthermore, we employ a neural network algorithm to enable automated data analysis and quantitative extraction of nanoscale electrical information. Our findings establish an invaluable sensing platform and readout mechanism, enhancing the understanding of exciton excitations and their applications in the quantum realm.