| Project Detail |
The world is currently on the verge of a new technological revolution, rooted on the possibility of harnessing unique properties of quantum mechanics such as entanglement to implement novel paradigms for computation. Semiconductor quantum dots are excellent candidates to become the sources at the heart of future photonic quantum technologies due to their capability of emitting single and even entangled photons. However, the presence of a fine structure splitting (FSS) between the excitonic levels significantly degrades the quality of the entangled emission from quantum dots and causes the latter to emit random entangled states instead of always the same Bell’s one: this pervasive problem has proved to be a major hindrance and prompted significant efforts to devise mitigation strategies.
All the approaches implemented so far assume that, in order to prevent the degradation of entangled photon emission, its prime cause, the fine structure splitting of the source, should be removed. Several approaches have yielded excellent results in this sense, but at the cost of unwanted side-effects or increases in fabrication complexity and introduction of additional challenges for photonic integration.
I propose to implement a complete paradigm shift in the search for a solution to this problem and show that entanglement restoral can be achieved after the emission of the photons from the source: as the latter emits a statistical mixture of entangled states when an FSS is present, and entanglement is not destroyed on a fundamental level, entanglement restoral can in principle be achieved by applying a sequence of logic gates that transforms any component of the ensemble to the same Bell state.
I propose to implement this approach and show its superiority for integrated quantum photonics by developing the world’s first fast photonic circuit in a Lithium Niobate platform designed to manipulate polarization-entangled photons, and fully integrate a quantum dot on the photonic chip. |
