Quantopticon has been awarded a €175,000 ($198,418) grant from the European Space Agency (ESA), along with collaborators from experimental groups in the University of Oxford and Technical University of Munich. Together, the team will develop high-quality single-photon sources for the first European quantum encryption satellite.
Quantopticon is developing simulation software for designing and optimizing quantum photonic devices. Called Quantillion, the software models the behavior of quantum photonic devices driven by light pulses with unparalleled accuracy and has applications in quantum computing and ultra-secure quantum communications.
The Guildford, UK-based company was founded in 2017 by mother-daughter duo Gaby Slavcheva, chief scientific officer, and Mirella Koleva, CEO, who are participating in the Duality Accelerator to catalyze further development of Quantopticon’s offerings and reach.
Duality is led by the Polsky Center for Entrepreneurship and Innovation at the University of Chicago and the Chicago Quantum Exchange (CQE), along with founding partners, the University of Illinois Urbana-Champaign, Argonne National Laboratory, and P33.
“Advanced design tools are critical for the progress of any technology platform, and this will be no less true for quantum technologies,” said Slavcheva. For the ESA project, the company will develop advanced modeling tools for semiconductor quantum-dot based single-photon sources, which are key enabling components of quantum communication networks. These networks are “un-hackable” channels for communicating through light – the security of which is guaranteed by the laws of quantum mechanics.
As Slavcheva explained, unamplified optical fiber links can transmit data up to several hundred kilometers via Quantum Key Distribution (QKD). “There is a clear need to increase this range by introducing signal-booster stations,” she said. “Launching these innovative systems on satellites solves this problem, as free-space light transmission suffers minimal absorption and scattering in Earth’s atmosphere, and overcomes issues with ground-based beaming due to Earth’s curvature.”
While satellites are one avenue to extending the QKD range globally, implementation of the infrastructure is still in the early stages, Slavcheva noted. “Many aspects of satellite QKD need further assessment and advancement,” she said. Mainly, satellite-based quantum communications are extremely challenging in respect to payload: “The launching cost scales up with the spacecraft dimension, weight, and power consumption,” said Slavcheva. This makes a lightweight, compact, low-power payload design highly desirable.
One solution to this challenge is the utilization of semiconductor quantum dot technology. Quantum dots are nanometer size islands of one semiconductor within another, and, as such, can be easily integrated on a chip. Additionally, quantum dots are one of the most promising solid-state single-photon sources: they are bright, robust, fast, scalable, and generate on-demand single photons with >99% fidelity. Most importantly, Quantopticon’s computer simulations can establish the parameters needed for reliably and repeatedly producing single- and entangled-photon states for robust QKD protocols that are not vulnerable to security attacks.
“We will develop a physical single-photon source device based on a single semiconductor quantum dot embedded in a micropillar optical cavity that allows for generation of high-quality and high-indistinguishability photons on demand,” said Slavcheva.
Using Quantopticon’s design blueprint, the prototype devices will initially be fabricated at the UK’s National Epitaxy Facility. The devices will be further processed at the Technical University of Munich, Germany, and will be tested and characterized at the University of Oxford, UK. “The raw data will be compared with our model predictions and the quantum device characteristics and parameters will be optimized to produce an optimized blueprint,” added Slavcheva. “Our efforts will contribute to unlocking the ability to mass-produce optimized single-photon sources, not only for QKD satellite communications but also for virtually all applications in quantum information processing.”