Researchers from NIST and the University of Maryland have achieved a significant breakthrough in quantum interference between two photons of different colors. The experiment demonstrates interference between red (780 nm) and blue (493 nm) photons, which could be crucial for future quantum computing and communication systems.
The key technical achievement was creating two separate photon sources in different buildings, then making the blue photons indistinguishable from the red ones using a special crystal. The photons were then sent through a 150-meter optical fiber to meet and interfere with each other.
The resulting quantum correlation between the photons could potentially be used for quantum information processing, such as connecting distant quantum processors in a quantum internet. The next step would be to entangle the photons with their respective quantum memory systems (rubidium atoms and trapped ions) to enable transfer of quantum information between them.
This experiment brings us closer to practical quantum computing by demonstrating the necessary quantum interference and entanglement between different types of photons. The next steps involve integrating these photons with quantum memory systems to enable practical quantum information processing and communication.
Source: https://www.nist.gov/news-events/news/2019/12/new-playbook-interference
Keywords: quantum interference, quantum correlation, entanglement, photons, quantum computing, quantum information
