The realisation of quantum networks is one of the major challenges of modern physics. Now, new research shows how high-quality photons can be generated from 'solid-state' chips, bringing us closer to the quantum 'internet'.
The number of transistors on a microprocessor continues to double every two years, amazingly holding firm to a prediction by Intel co-founder Gordon Moore almost 50 years ago.
If this is to continue, conceptual and technical advances harnessing the power of quantum mechanics in microchips will need to be investigated within the next decade. Developing a distributed quantum network is one promising direction pursued by many researchers today.
A variety of solid-state systems are currently being investigated as candidates for quantum bits of information, or qubits, as well as a number of approaches to quantum computing protocols, and the race is on for identifying the best combination. One such qubit, a quantum dot, is made of semiconductor nanocrystals embedded in a chip and can be controlled electro-optically.
Single photons will form an integral part of distributed quantum networks as flying qubits. First, they are the natural choice for quantum communication, as they carry information quickly and reliably across long distances. Second, they can take part in quantum logic operations, provided all the photons taking part are identical.
Unfortunately, the quality of photons generated from solid-state qubits, including quantum dots, can be low due to decoherence mechanisms within the materials. With each emitted photon being distinct from the others, developing a quantum photonic network faces a major roadblock.
Now, researchers from the Cavendish Laboratory at Cambridge University have implemented a novel technique to generate single photons with tailored properties from solid-state devices that are identical in quality to lasers. Their research is published today in the journal N
|Contact: Mete Atature|
University of Cambridge