Single-photon sources are assuming an increasingly important role in the era of the second quantum revolution. Encrypted information exchange of the future will be based on quantum key distribution, which in turn needs the availability of reliable single-photon sources. In the realm of the possible candidates for these sources, transition metal dichalcogenides are gaining a growing success. These materials have a crystalline structure which favors their exfoliation into atomically thin layers. Two-dimensional materials are a virgin ground for discoveries in fundamental physics but recently proved to be also an already mature field for technological application. It is possible to induce single-photon emitters in monolayers of these materials, in a controlled position and with a scalable process. Their emission properties can also be tuned with different methods, including strain application, with several works appearing in the literature.
Very recently, the single-photon emitters in transition metal dichalcogenides were coupled to a photonic structure to enhance their emission rate, a fundamental request towards their implementation into efficient devices for quantum protocols. The scope of this project is to connect the missing pieces of this puzzle and fabricate a transition metal dichalcogenides single-photon source, with tunable energy and high repetition rates.
To do so we will exploit the knowledge developed in the last years in our group in Sapienza University together with the ongoing collaborations with universities and excellent research centers in Europe. The Nanophotonics group in the Physics Department of our university will provide an entire laboratory with several researchers and Ph.D. students working on the topic and their expertise in strain tuning technologies.
Transition Metal Dichalcogenides are starting to gain growing attention in the world of quantum optics and quantum information. They offer a rather simple and cheap fabrication - the exfoliation procedure from the bulk sample needs just a microscope and a piece of tape - with options to make the process scalable. To our knowledge, there is no publication about TMD-based, energy-tunable, Purcell-enhanced, single-photon emitters and this work would represent an improvement of the state of the art in this young and growing field. The realization of this device would add a new candidate to the field of single-photon sources, with great advantages in the device throughput and the potential for scalability and the creation of a commercial system. Several scientific groups would be interested in testing this type of device for their experiments, also considering the costs and the necessary equipment of the only commercially available system [7].
We, therefore, think that such a device would represent an improvement in the state of the art with the potential to create new research and commercial implications.