Researchers from the University of Waterloo have split one photon in the three for the first time. The occurrence is described as the first of its kind and uses something called the spontaneous parametric down-conversion method or SPDC. The experiment created what the researchers call a non-Gaussian state of light.
A non-Gaussian state light is considered a critical ingredient in gaining quantum advantage. Scientist Chris Wilson says that it was understood that there were limits on the type of entanglement generated with the two-photon version. The results of the experiment form the basis of an exciting new paradigm for three-photon quantum optics.
The scientists also noted that the new research brings the team past the known ability to split one photon into two entangled daughter protons. The team feels that they have opened a new area of exploration. Wilson notes that the two-photon version has been a workhorse for quantum research for the last three decades.
In the research, Wilson and his team used microwave photons to stretch the known limits of SPDC. The experimental implementation used a superconducting parametric resonator. The team says that the results showed a strong correlation among the three photons generated at different frequencies. Researchers are continuing to work with the goal of showing that the photons are entangled.
Wilson says that non-Gaussian states and operations are critical for obtaining the quantum advantage. He says that they are difficult to simulate and model classically, which has resulted in “a dearth of theoretical work for the application.” The team hopes that eventually, their work will lead to the development of optical quantum computing using superconducting units. The team believes that three photons will overcome current limits.