Grant: Alliance Grants

Quantum computing may one day solve problems with enormous societal impact that today are intractable for even the largest supercomputers, including examples that address climate change - e.g., from catalysts to efficiently extract carbon dioxide from the atmosphere, to higher energy density batteries to extend the range of electric vehicles, or reducing the high cost and carbon footprint of fertilizers. Other far-reaching applications include the design of novel therapeutics. Despite the global effort however, quantum hardware and software must still evolve considerably before they are ready to address these inspiring questions. Photonic quantum computing, pioneered by Canada's Xanadu Quantum Technologies, relies on high-efficiency superconducting transition-edge sensors (TES) that can detect weak optical signals at the telecom wavelength, with single-photon sensitivity. Yet, since the superconducting transition temperatures of elemental metal films are below the liquid-helium boiling point, these TES currently suffer from an operation temperature below 1K, imposing a major technical hurdle towards upscaling (i.e., increasing the number of qubits) for photon-based quantum computation. Working with Xanadu, we will tackle this critical challenge with a novel approach based on the microfabrication of quantum devices using the highest transition-temperature (Tc) superconductors available: high-Tc cuprates. Starting from single crystal growth and quantum material design concepts pioneered at QMI, and implementing a novel microexfoliation technique, we will develop superconducting, monolayer- thin single-photon detectors operating at temperatures even higher than the boiling point of nitrogen. This new class of high-temperature single-photon detectors will have dramatically improved performance in the infrared range, and provide a viable and scalable platform for photonic quantum computing, while advancing Canada to the forefront of this rapidly growing field.