Researchers Demonstrate 3-Photon Split in the Microwave Domain

Facebook X LinkedIn Email
Researchers at the University of Waterloo have directly split one photon into three. To do so, they created a non-Gaussian state of light using spontaneous parametric down-conversion (SPDC).

Traditional SPDC, which splits a high-energy pump photon into two lower-energy photons, is a common way to produce entangled photon pairs. However, directly generating photon triplets through a single SPDC process has remained elusive.

The researchers used microwave photons to stretch the known limits of SPDC. Using a flux-pumped superconducting parametric cavity, they demonstrated direct three-photon SPDC, with photon triplets generated in a single cavity mode or split between multiple modes. The triplet source was bright, producing a propagating photon flux comparable to ordinary two-photon SPDC. The researchers observed strong three-photon correlations in the output photons. The symmetry properties of these correlations allowed them to “fingerprint” how the photons were created.

The observed states were strongly non-Gaussian, which, according to the researchers, has important implications for potential applications. “Non-Gaussian states and operations are a critical ingredient for obtaining the quantum advantage,” professor Chris Wilson said. “They are very difficult to simulate and model classically, which has resulted in a dearth of theoretical work for this application.”

The observed non-Gaussian, third-order correlations could represent an important step forward in quantum optics and could have a strong impact on quantum communication with microwave fields as well as continuous-variable quantum computation.

“The two-photon version has been a workhorse for quantum research for over 30 years,” Wilson said. “We think three photons will overcome the limits and will encourage further theoretical research and experimental applications and hopefully the development of optical quantum computing using superconducting units.” Through ongoing work, the researchers aim to show that the photons are entangled.

The research was published in Physical Review X (  

Published: February 2020
quantum optics
The area of optics in which quantum theory is used to describe light in discrete units or "quanta" of energy known as photons. First observed by Albert Einstein's photoelectric effect, this particle description of light is the foundation for describing the transfer of energy (i.e. absorption and emission) in light matter interaction.
quantum entanglement
Quantum entanglement is a phenomenon in quantum mechanics where two or more particles become correlated to such an extent that the state of one particle instantly influences the state of the other(s), regardless of the distance separating them. This means that the properties of each particle, such as position, momentum, spin, or polarization, are interdependent in a way that classical physics cannot explain. When particles become entangled, their individual quantum states become inseparable,...
An electromagnetic wave lying within the region of the frequency spectrum that is between about 1000 MHz (1 GHz) and 100,000 MHz (100 GHz). This is equivalent to the wavelength spectrum that is between one millimeter and one meter, and is also referred to as the infrared and short wave spectrum.
Research & TechnologyeducationAmericasquantum communicationsquantum opticsOpticsCommunicationsquantum entanglementspontaneous parametric down-conversionPhoton TripletsmicrowaveTech Pulse

We use cookies to improve user experience and analyze our website traffic as stated in our Privacy Policy. By using this website, you agree to the use of cookies unless you have disabled them.
Photonics Spectra Optical Design Summit 2024LIVE NOW: Designing Freeform Optics for Illumination X