The research team from Graphene Flagship recently made use of layered materials for creating one hundred percent electrical quantum LEDs that are capable of emitting single photons. The instruments are believed to be potent enough to behave as chip photons sources for applications related to quantum information. These LEDs are derived from some very thin layers of various materials all of which stack together to formulate heterostructure. The electrical current is then injected in the device that tunnels from a single layered graphene, it then goes through a tunnel barrier of some boron nitride layers and ends up inside a bi or mono-layered Transition Metal Dichalcogenide (TMD). Over this layer, the electrons again combine with the holes to produce single photons.
According to the tea, the single photon generation previously depended heavily on optical excitation; these were some large scale optical systems installed with precisely aligned optical components and lasers. Professor Mete Atature from Cavendish Laboratory from the University of Cambridge, explains, “In a scalable circuit, we need fully integrated devices that we can control by electrical impulses, instead of a laser that focuses on different segments of an integrated circuit. For quantum communication with single photons, and quantum networks between different nodes – for example, to couple qubits – we want to be able to just drive current and get light out. There are many emitters that are optically excitable, but only a handful are driven electrically.”
The team further added, the instruments designed by them run on current less than 1µA , this ensures that a single photon act dominates the features of emission. A technology and science officer from Graphene Flagship Management Panel, Prof Andrea Ferrari, also adds, “We are just scratching the surface of the many possible applications of devices prepared by combining graphene with other insulating, semiconducting, superconducting or metallic layered materials. In this case, not only have we demonstrated controllable photon sources, but we have also shown that the field of quantum technologies can greatly benefit from layered materials. “We hope this will bring synergies between the Graphene Flagship and its researchers, and the recently announced Quantum Technologies Flagship, due to start in the next few years. Many more exciting results and applications will surely follow.”