Single-exciton trapping in an electrostatically defined two-dimensional semiconductor quantum dot

Interlayer excitons (IXs) in 2D semiconductors have long lifetimes and spin-valley coupled physics, with a long-standing goal of single exciton trapping for valleytronic applications. In this work, we use nano-patterned graphene gate to create an electrostatic IX trap. We measure unique power-dependent blue-shift energy, where narrow linewidth emission exhibits discrete energy jumps. attribute these jumps quantized increases the number occupancy IXs within trap compare theoretical model assign lowest line recombination.