Waterloo scientists combine Nobel-prize winning physics and chemistry to enhance quantum interaction efficiency and security. Credit: SciTechDaily.comUniversity of Waterloo scientists integrate Nobel prize-winning concepts to accomplish clinical breakthrough.Researchers at the University of Waterloos Institute for Quantum Computing (IQC) have brought together 2 Nobel prize-winning research study concepts to advance the field of quantum communication.Scientists can now effectively produce nearly best knotted photon sets from quantum dot sources.Entangled photons are particles of light that remain linked, even across large ranges, and the 2022 Nobel Prize in Physics recognized experiments on this subject. Combining entanglement with quantum dots, a technology acknowledged with the Nobel Prize in Chemistry in 2023, the IQC research team intended to optimize the process for creating knotted photons, which have a wide array of applications, including protected communications.Enhancing Quantum Efficiency and Entanglement” The mix of a high degree of entanglement and high performance is needed for interesting applications such as quantum essential distribution or quantum repeaters, which are imagined to extend the range of safe quantum communication to an international scale or link remote quantum computer systems,” said Dr. Michael Reimer, professor at IQC and Waterloos Department of Electrical and Computer Engineering. “Previous experiments only determined either near-perfect entanglement or high efficiency, however were the first to attain both requirements with a quantum dot.” The knotted photon source, an indium-based quantum dot embedded in a semiconductor nanowire (left), and a visualization of how the entangled photons are effectively drawn out from the nanowire. Credit: University of WaterlooBy embedding semiconductor quantum dots into a nanowire, the researchers produced a source that develops near-perfect entangled photons 65 times more efficiently than previous work. This brand-new source, established in partnership with the National Research Council of Canada in Ottawa, can be thrilled with lasers to generate entangled sets on command. The scientists then used high-resolution single photon detectors supplied by Single Quantum in The Netherlands to increase the degree of entanglement.Overcoming Historical Challenges and Future Applications” Historically, quantum dot systems were afflicted with an issue called great structure splitting, which causes a knotted state to oscillate in time. This implied that measurements taken with a sluggish detection system would avoid the entanglement from being measured,” stated Matteo Pennacchietti, a PhD student at IQC and Waterloos Department of Electrical and Computer Engineering. “We conquered this by integrating our quantum dots with a precise and really fast detection system. We can generally take a timestamp of what the entangled state looks like at each point during the oscillations, whichs where we have the best entanglement.” To showcase future communications applications, Reimer and Pennacchietti dealt with Dr. Norbert Lütkenhaus and Dr. Thomas Jennewein, both IQC professor and professors in Waterloos Department of Physics and Astronomy, and their groups. Utilizing their brand-new quantum dot entanglement source, the researchers simulated a protected interactions method referred to as quantum crucial circulation, showing that the quantum dot source holds substantial guarantee in the future of secure quantum communications.This research, “Oscillating photonic Bell state from a semiconductor quantum dot for quantum key distribution,” was just recently published in Communications Physics by Pennacchietti, Reimer, Jennewein, Lütkenhaus, Brady Cunard, Shlok Nahar, and Sayan Gangopadhyay from IQC, together with their collaborators Dr. Mohd Zeeshan, Dr. Philip Poole, Dr. Dan Dalacu, Dr. Andreas Fognini, Dr. Klaus Jöns, and Dr. Val Zwiller.Reference: “Oscillating photonic Bell state from a semiconductor quantum dot for quantum key distribution” by Matteo Pennacchietti, Brady Cunard, Shlok Nahar, Mohd Zeeshan, Sayan Gangopadhyay, Philip J. Poole, Dan Dalacu, Andreas Fognini, Klaus D. Jöns, Val Zwiller, Thomas Jennewein, Norbert Lütkenhaus and Michael E. Reimer, 24 February 2024, Communications Physics.DOI: 10.1038/ s42005-024-01547-3.