二维超导量子比特系统的随机量子态量子纠缠度量

Quantum computation is a new computational method in comparison with classical computing. Extremelly high speedup over classical computing in many key fields have be developed. Among many different physical realizations, superconducting quantum computation is one of the most applicable realizations. By focusing on the development of higher dimentional superconduting quantum computation, this project is proposed to overcome several key issues, including the design of the qubit structure, the design of coupling between neighbouring qubits, the output of the high density circuits on the chip, etc. After all these developments, this project will realize a structure with high efficiency qubit layout. Base on the new layout, this project will focus on the entanglement entropy of random quantum states in a 2D qubit structure. To be more specific, by performing randomized measurement, this project will study the relationship between initial states and multipartite entanglement entropy. Meanwhile, with the variation of evolution time, the time-dependent entropy evolution of the many qubit system will be studied. Furthermore, the Area Law of the quantum entanglement in 2D systems will be experimentally studied.

量子计算由于其完全不同于经典计算机的运算方式，在众多关键领域中展现出了颠覆性的计算能力优势。超导量子比特方案是最有可能实用化的方向之一。本项目从实现二维的超导量子芯片设计出发，拟解决其中的一些关键问题，包括比特结构设计，比特间耦合方式选择，芯片高密度线引出等方式，从而实现有效的新型二维超导量子芯片方案，为实现中等规模的比特结构奠定技术基础。在此基础上，本项目将着眼于量子纠缠领域的二维量子比特量子纠缠态的纠缠度量，使用随机测量的方式估计系统的多体纠缠熵，并研究其随比特初始状态及随时间变化的演化方式，探究量子纠缠面积律。

量子计算由于其强大的算力优势，成为了颠覆当前经典计算机模式、突破算力瓶颈的关键技术路线之一。超导量子比特方案由于其具有可拓展性、操控方便等优势，成为最有希望实用化的量子计算实现方案之一。本项目从实现二维的超导量子芯片设计出发，以实现量子处理器维度拓展和比特数目提升为主要目标，通过结合当前工艺技术与量子芯片特点，成功地实现了量子处理器维度和数目的提升，最终实现了二维结构的超导量子处理器，并搭建了62量子比特的超导量子计算原型机“祖冲之号”。在此基础上，项目开展了一系列的量子模拟的研究，对于量子行走、热化与局域化等现象进行了深入的实验研究。本项目也为实现量子计算优越性提供了技术积累和支持。