Defects in semiconductors: atomic-like systems in a solid-state host - Kai-Mei Fu

Defects provide potentials for quantum particles (electrons and holes) in crystals. In high purity crystals, the quantum-confined particles can behave similarly to atoms, enabling atomic-like physics in a solid-state environment that is amenable to device integration. In the first part of my talk, I present a novel, highly homogeneous 2D potential for excitons that is ubiquitous in zinc-blende semiconductors, the stacking fault. The narrow optical transitions enable us to observe a magnetic non-reciprocity effect in which the energy of the excitonic emission depends on the sign of the magnetic field. This effect, due to conservation of the exciton two-dimensional momentum, provides direct evidence that excitons are mobile and enables a measurement of the giant exciton dipole moment (~10 nm). The large dipole moment combined with the high optical homogeneity suggests the stacking fault as a novel platform to study coherent phenomena in interacting excitonic gases. In the second part of the talk, I switch gears to present work in defect device integration and present my group’s on-going effort toward chip-scale integrated quantum optics utilizing the nitrogen-vacancy center in diamond.