A novel source of quantum light: harnessing cascaded downconversion as a resource for quantum technologies

点击翻译按钮获取中文摘要

The first quantum revolution, spurred by the discovery of quantum physics, helped us understand how the world works and led to the development of computer chips and lasers. We are currently on the verge of a second quantum revolution, which will come from technologies designed from the ground up to directly exploit quantum phenomena. Such technologies are expected to transform computing, through quantum processors providing, for certain tasks, exponential speedups relative to today's computers. They will also revolutionize metrology and sensing, with sensors breaking through the sensitivity limits of current technologies, and cryptography, with quantum protocols able to provide absolutely secure communications. A critical requirement for several quantum technologies is the availability of practical methods to produce light possessing quantum properties. Light has the advantage of being able to hold and transfer quantum data effectively, making quantum light sources a key technology for optical quantum computers. Light is also the sole truly feasible method of transferring quantum data quickly over long distances; quantum light sources are therefore an essential requirement for quantum communication and for the development of the quantum internet. Over the last few years, my group has explored how a novel method of producing quantum light, cascaded downconversion, can be used as an enabling resource for various quantum information applications and as a tool to explore fundamental quantum physics. Our efforts have been extremely fruitful, leading to many significant discoveries. While these results conclusively demonstrate the relevance of cascaded downconversion for both fundamental and technological applications, certain roadblocks remain, preventing its widespread adoption for practical use. Most importantly, the method currently suffers from low efficiencies, as even the most efficient nonlinear crystals only convert one out of every million photons. This has limited cascaded downconversion to production rates insufficient for most real-world scenarios. With this new Discovery Grant, I propose a research program aimed at harnessing the potential of cascaded downconversion for quantum information processing. This will be done both through technical developments aimed at addressing the current challenges associated with the process, and by demonstrating its usefulness in implementing a variety of optical quantum information protocols and applications. This research program will be of significant benefit to Canadians. First, through the generation of knowledge and novel technologies of immediate relevance in the burgeoning Canadian quantum sector. Second, by training students and other highly qualified personnel to provide them with the skills required to be active participants in this new Canadian quantum industry which is currently in dire need of skilled workers.