A team of researchers from the Humboldt-Universität zu Berlin and the Ferdinand-Braun-Institut has succeeded in generating photons with stable frequencies emitted from quantum light sources.
“Diamond material is of great importance for future technologies such as the quantum internet,” said senior author Professor Tim Schröder from the Humboldt-Universität zu Berlin and his colleagues.
“Special defect centers can be used as qubits and emit single light particles that are referred to as single photons.”
“To enable data transmission with feasible communication rates over long distances in a quantum network, all photons must be collected in optical fibers and transmitted without being lost.”
“It must also be ensured that these photons all have the same color, i.e., the same frequency.”
“Fulfilling these requirements has been impossible — until now.”
In their research, the authors were able to generate and detect photons with stable photon frequencies emitted from quantum light sources, or, more precisely, from nitrogen-vacancy defect centers in diamond nanostructures.
“This was enabled by carefully choosing the diamond material, sophisticated nanofabrication methods, and specific experimental control protocols,” they said.
“By combining these methods, the noise of the electrons, which previously disturbed data transmission, can be significantly reduced, and the photons are emitted at a stable (communication) frequency.”
The team’s results show that current communication rates between spatially separated quantum systems can prospectively be increased more than 1,000-fold — an important step closer to a quantum internet.
“We integrated individual qubits into optimized diamond nanostructures,” they said.
“These structures are 1,000 times thinner than a human hair and make it possible to transfer emitted photons in a directed manner into glass fibers.”
“However, during the fabrication of the nanostructures, the…
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