Over the last decades, there has been tremendous progress in the controlled fabrication of colloidal semiconductor nanocrystals. One of the potential applications of such structures is as sources for quantum states of light. During the past two and a half years we have made significant progress in constructing structures that function as very good single photo emitters at room temperature, and have been able to fabricate nanostructures that emit a small number of photons upon photoexcitation which almost always exceeds unity but rarely exceeds three. We are currently aiming for narrowing the distribution of the number of emitted photons from such structures, getting as close as we can to deterministic emitters of photon pairs. We are currently expanding these studies to low temperatures, aiming at generating quantum correlations between these photon pairs. All these will potentially function as future components in quantum devices.
Harnessing the ability to generate true single-photon emitters, we have demonstrated that this quantum resource can be used to enhance the spatial resolution in optical imaging. In particular, we have shown that the resolution of an optical microscope can be enhanced by up to four times better than the diffraction limit in a confocal setup harnessing single-photon emission. We are currently working on establishing this method as a general-purpose add-on to standard confocal microscopes both in terms of methods and in terms of hardware.
