KTH Royal Institute of Technology Researchers Develop New Light Emitters for Quantum Circuits
(HPC.Wire) KTH Royal Institute of Technology Professor Val Zwiller says that in order to integrate quantum computing seamlessly with fiber-optic networks—which are used by the internet today—a more promising approach would be to harness optical photons. “The photonic approach offers a natural link between communication and computation,” he says. “That’s important, since the end goal is to transmit the processed quantum information using light.”
But in order for photons to deliver qubits on-demand in quantum systems, they need to be emitted in a deterministic, rather than probabilistic, fashion. This can be accomplished at extremely low temperatures in artificial atoms, but today the research group at KTH reported a way to make it work in optical integrated circuits—at room temperature.
The new method enables photon emitters to be precisely positioned in integrated optical circuits that resemble copper wires for electricity, except that they carry light instead, says Associate Professor Ali Elshaari.
The researchers harnessed the single-photon-emitting properties of hexagonal boron nitride (hBN), a layered material. hBN is a compound commonly used is used ceramics, alloys, resins, plastics and rubbers to give them self-lubricating properties. They integrated the material with silicon nitride waveguides to direct the emitted photons.
The researchers harnessed the single-photon-emitting properties of hexagonal boron nitride (hBN), a layered material. hBN is a compound commonly used is used ceramics, alloys, resins, plastics and rubbers to give them self-lubricating properties. They integrated the material with silicon nitride waveguides to direct the emitted photons.
Quantum circuits with light are either operated at cryogenic temperatures—plus 4 Kelvin above absolute zero—using atom-like single photon sources, or at room temperature using random single photon sources, Elshaari says. By contrast, the technique developed at KTH enables optical circuits with on-demand emission of light particles at room temperature.
