Researchers from the Institute for Quantum Computing (IQC), led by Professors Kyung Soo Choi and Thomas Jennewein, both faculty members with the Department of Physics & Astronomy at the University of Waterloo, received funding from the Korea Institute of Science and Technology (KIST) to develop critical building blocks of a quantum network.
The creation of a “quantum web” would offer opportunities for quantum information science, connecting quantum processors, not just locally, but one day across the world. The funding of more than $500,000 over the next three years will help enable Choi develop the technology for lithographic functional quantum optical circuits with ultracold atoms, while Jennewein develops efficient narrow-band entangled photon sources.
Researchers at KIST are also developing similar disruptive quantum technologies. Their focus is to develop light-matter quantum interfaces between quantum memory based upon defect centres in diamond and photon pair sources using parametric down-conversion crystals.
“The collaboration with the University of Waterloo is an important step to expand our core research activities at KIST into the realm of quantum physics, ” said Dr. Yong-Su Kim, a senior scientist in the Center of Quantum Information Science and the principal investigator for the counterpart grant in KIST. “Quantum information science has become a major national agenda for the Korean government, and we are excited to join forces with IQC, which is recognized as one of the premier quantum research centres in the world.”
Choi’s focus on building quantum memories is based on the use of photonic crystal waveguides coupled to ultracold single atoms and quantum degenerate gases. His team is engineering functional quantum circuits in a scalable quantum network. Photonic crystals enhance the interaction between a single atom and photon so that the photon can transfer information between single atoms. In a complimentary fashion, the atoms help single photons interact.
“We are excited to participate and contribute to the early stage of development in an emerging field between cold atom physics and nanophotonics,” said Choi, the principal investigator of the project in Waterloo. “The funding from Korea will help our teams at KIST and IQC to do world-class research.”
In Jennewein’s lab, he and his team are working towards creating photon pairs that are optimal for the free-space transmission of quantum information over their pre-existing test bed systems. To do this, the researchers are building a high-rate, narrow-band photon pair source using a nonlinear optical waveguide. The nonlinear conversion is extremely strong and generates very bright, entangled photons (hundreds of millions of pairs per second), with a very well-defined optical frequency. While many of these photons will be scattered or absorbed when travelling through free space, due to the high rate of photons, a sufficient number of the photons will be received. The ability to produce a large number of photons within the well-defined frequency is an important step towards long-distance free-space quantum communication. “We are very excited to participate in this partnership with KIST, and to work on advancing the speed and reliability of quantum optical free-space links together,” said Jennewein.
The funding follows from the Memorandum of Understanding that IQC signed in September 2014 with KIST to expand research partnerships in the field of quantum information science. “We signed the agreement with KIST to accelerate the development of quantum technology for the benefit of both countries,” said Raymond Laflamme, executive director of IQC. “In addition, this strong collaboration between research groups will develop building blocks for the eventual networks of quantum devices.”