Quantum Information Processing with Bosonic Systems

人们普遍预计，量子技术将给计算、通信、传感等众多技术领域带来革命性的变化。目前大多数量子技术研究都集中在两能级(量子比特)系统上，但这种方法在可扩展性和信息容量方面存在重大缺陷。在我的NSERC发现计划中，我将瞄准一个有前途的替代方案：玻色量子技术。与量子比特不同，每个玻色子模式都提供了有效的无限量子能级来存储信息。此外，玻色子系统在许多平台(如光子、机械振荡器)中无处不在，有些甚至包含比量子比特设备多10000倍的单位。然而，分析巨大的玻色子自由度是具有挑战性的，所以玻色子技术的几乎所有方面，包括应用、信息编码和设备分析，都比量子比特的同行研究得少。在我过去成功填补这些理论空白的基础上，我的计划的长期目标是进一步提高玻色量子技术的实用性。在接下来的5年里，我的团队将致力于三个短期目标：1：为开放量子系统(与浴缸相互作用的系统)开发玻色子模拟器。高度可扩展的玻色子平台允许模拟系统和BASH。我们将制定这种模拟器的体系结构，并分析其由于实际缺陷而产生的误差。2：制定提取连续变量(CV)资源的方案。CV团簇态是一类可以有效产生的资源丰富的玻色态(纠缠)，但由于固有的误差，它的实用性还存在争议。我们将分析它的数学结构，以便设计出将CV纠缠转换为量子比特纠缠的程序。量子比特纠缠有着众多的应用和研究得很好的纠错策略。3：改进巡回模式和本地化模式之间的混合界面。我们将探索高速控制、回收不完全纠缠和非线性相互作用等策略，以便在远程设备上更有效地分配量子资源。这些工作将为一种基本上未被探索、具有难以置信潜力的量子技术做出变革性的贡献。具体地说，我们的成果将：1)促进开发功能强大的模拟器来研究开放的量子现象，例如化学和生物过程，这些过程具有广泛的兴趣，但对资源的要求太高，无法用今天的计算机来模拟；2)导致一种新的“自上而下”的量子计算机，它可以避开现有量子比特计算机的可扩展性瓶颈；3)使高质量的量子网络能够有不同的应用，例如在保密通信和精确远程复制方面。此外，在我的项目中培训的HQP将成为量子技术方面的专家。我的项目中的技术进步和训练有素的人员都将有助于推动加拿大蓬勃发展的量子产业；这将为加拿大带来社会和经济利益。

Quantum technology is widely anticipated to revolutionize numerous technological areas, such as computation, communication, sensing. Most current quantum technology research has focused on two-level (qubit) systems, but this approach suffers from major drawbacks in scalability and information capacity. In my NSERC Discovery program, I will target a promising alternative: bosonic quantum technology. Unlike a qubit, each bosonic mode offers effectively infinite quantum levels to store information. Furthermore, bosonic systems are ubiquitous in many platforms (e.g. photons, mechanical oscillators), some even incorporate 10,000 times more units than qubit devices. Nevertheless, analyzing the enormous bosonic degree of freedom is challenging, so nearly all aspects of bosonic technology, including applications, information encoding, and device analysis, have been less studied than qubit counterparts. Building on my past successes in filling some of these theoretical gaps, the long-term goal of my program is to further improve the practicality of bosonic quantum technology. In the next 5 years, my team will address three short-term objectives: 1: Develop bosonic simulator for open quantum systems (systems interacting with a bath). Highly scalable bosonic platforms allow both system and bath to be simulated. We will formulate the architecture of such simulator and analyze its error due to practical imperfections. 2: Devise protocol to extract continuous-variable (CV) resources. CV cluster state is the class of resourceful bosonic state (entanglement) that can be efficiently generated, but its utility is debatable due to intrinsic error. We will analyze its mathematical structure so as to devise procedures to convert the CV entanglement to qubit entanglement, which has numerous applications and well-studied error correction strategies. 3: Refine hybrid interface between itinerant and localized modes. We will explore strategies, e.g. high-speed control, recycling imperfect entanglement, and non-linear interaction, to distribute quantum resources more efficiently in remote devices. These works will make transformative contributions to a largely unexplored type of quantum technology with incredible potential. Specifically, our results will: 1) facilitate the development of a powerful simulator for studying open quantum phenomena, e.g. chemical and biological processes, which are of broad interest but too resource demanding to simulate with today's computers; 2) lead to a new `top-down' quantum computer that can evade the scalability bottleneck of existing qubit computers; 3) enable high-quality quantum networks that have diverse applications, e.g. in secure communication and precise telescopy. Additionally, the HQP trained in my program will become experts in quantum technology. Both the technological advancements and trained personnel in my program will help fuel Canada's blooming quantum industry; this will bring social and economic benefits to Canada.