Source: Xin'an Evening News
# Introduction #
The reporter learned from the University of Science and Technology of China that recently, the university's scientific research team has made important progress in quantum computing of superconducting quantum and optical quantum systems, making China the only country in the world to reach the milestone of quantum computing superiority in two physical systems.
01
The University of Science and Technology of China Successfully Realizes the "Superiority of Quantum Computing" in Superconductivity System
The research team composed of Pan Jianwei, Zhu Xiaobo and Peng Chengzhi of the Institute of Quantum Information and Quantum Science and Technology Innovation of the Chinese Academy of Sciences of the University of Science and Technology of the University of Science and Technology of China cooperated with the Shanghai Institute of Technical Physics of the Chinese Academy of Sciences to build the 66-bit programmable superconducting quantum computing prototype "Zuchong No. 2", which realized the rapid solution of the "quantum random line sampling" task.
According to the existing theory, the speed of the quantum random line sampling problem handled by "Zuchong-2" is 7 orders of magnitude faster than that of the current fastest supercomputer, and the computational complexity is 6 orders of magnitude higher than the 53-bit superconducting quantum computing prototype "planewood" publicly reported by Google ("planewood" processing "quantum random line sampling" problem is 2 orders of magnitude faster than classical supercomputing), which is the first time that China has reached the "quantum computing superiority" milestone in the superconducting qubit system after the "nine chapters" of the optical quantum computing prototype , making china the only country that has reached this milestone in both physical systems. The paper was published in Physical Review Letters and Science Bulletin.
Zu Chong Zhi No. 2 quantum processor diagram
The solution of a specific problem by a quantum computer surpasses that of a supercomputer, that is, the superiority of quantum computing, and is the first milestone in the development of quantum computing, reaching this milestone requires coherent manipulation of more than 50 qubits. Superconducting qubits are internationally recognized as one of the physical systems that promise to enable scalable quantum computing. Pan Jianwei, Zhu Xiaobo, Peng Chengzhi and others have long aimed at the field of superconducting quantum computing, and in May 2021, they built the prototype "Zu Chong Zhi", which was the 62-bit superconducting quantum computing prototype with the largest number of qubits in the world at that time, and realized programmable two-dimensional quantum walking [Science 372, 948 (2021)].
On the basis of "Zu Chong No.", the team adopted a new flip-down welding 3D packaging process to solve the problem of large-scale bit integration, and successfully developed "Zu Chong No. 2", realizing the high-density integration of 66 data bits, 110 coupling bits, and 11 reads, and the maximum state space dimension reached 1019. Zuchong No.2 adopts an adjustable coupling architecture to achieve fast and accurate adjustment of the coupling intensity between bits, which significantly improves the fidelity of parallel quantum gate operation. Through quantum programming, the researchers achieved sampling of quantum random lines, demonstrating the programming ability of Zuchong-2 to execute arbitrary quantum algorithms. According to the optimized classical algorithm that has been published so far, the speed of processing the quantum random line sampling problem by "Zu Chong Zhi No. 2" is 7 orders of magnitude faster than the fastest supercomputer at present, and the computational complexity is 6 orders of magnitude higher than that of Google's "plane tree".
The successful demonstration of the superiority of quantum computing marks the second stage of quantum computing research, which begins to explore quantum error correction and recent applications. "Zuchong No.2" adopts a two-dimensional grid bit arrangement chip architecture, which is directly compatible with surface code quantum error correction algorithm, laying a foundation for quantum error correction and further realization of general-purpose quantum computing. At the same time, the parallel high-fidelity metric subgate manipulation ability and full programmability of "Zuchong-2" are expected to find practical applications in specific fields, and the expected applications include quantum machine learning, quantum chemistry, and quantum approximation optimization.
Pan Jianwei, academician of the Chinese Academy of Sciences: In the next step, we hope to achieve quantum error correction through 4 to 5 years of efforts, and on the basis of using quantum error correction, we can explore the use of some dedicated quantum computers or quantum simulation machines to solve some scientific problems with great application value. (According to CCTV video)
02
The University of Science and Technology of China successfully developed the 113-photon "Jiuzhang-2" quantum computing prototype
The research team composed of Pan Jianwei, Lu Chaoyang, Liu Naile and others from the University of Science and Technology of China cooperated with the Shanghai Institute of Microsystems of the Chinese Academy of Sciences and the National Parallel Computer Engineering Technology Research Center to develop theoretical and experimental methods for stimulated amplification of quantum light sources, constructed a quantum computing prototype "Jiuzhang-2" with 113 photons and 144 modes, and realized the phase programmable function, completing the rapid solution of the Gaussian Bose sampling task used to demonstrate the "superiority of quantum computing". According to existing theories, The Nine Chapters II processes Gaussian Bose sampling 1024 times faster than the fastest supercomputers available. This achievement once again refreshes the international technical level of optical quantum manipulation and further provides experimental evidence for quantum computing acceleration.
The paper was published in the form of "Editor's Recommendation" on October 26, 2021 in the internationally renowned academic journal Physical Review Letters. Barry Sanders, a renowned quantum physicist and professor at Calgary University in Canada, was also invited to transcribe a lengthy review on the Physics website, praising the work as an "exciting experimental masterpiece" and "an impressive cutting-edge advance."
Nine Chapter 2 Overall Installation Diagram (Draft: Lu Chaoyang, Peng Lichao)
In principle, quantum computers can obtain more computing power than classical computers in terms of some problems of great social and economic value through specific algorithms. As early as 1981, Feynman came up with the initial idea of quantum computing. The physical implementation of large-scale quantum computers is one of the major challenges at the forefront of science and technology in the world. For the development of fault-tolerant general quantum computing, because of its harsh fault-tolerant threshold and the number of large-scale qubits, there is still a big gap from the current level of human scientific and technological development.
Therefore, to achieve the physical implementation of quantum computing, the international academic community has taken a three-step roadmap. Among them, the first milestone, known academically as "quantum computing superiority", means to efficiently solve specific high-complexity mathematical problems that supercomputers cannot solve in a reasonable amount of time by manipulating nearly a hundred physical bits with high precision, experimentally and conclusively prove the idea of quantum computing acceleration proposed by Feynman forty years ago, and refute the "extended Church-Turing thesis".
Nine chapter two 144 mode interferometer (part) experimental photos (photo: Ma Xiaohan, Yang Jianrui, Li Feng, Deng Yuhao)
Photon-based Bose sampling and superconducting bit-based random line sampling are two important protocols for experiments to demonstrate the superiority of quantum computing. Pan Jianwei's team has been at the international leading level in optical quantum information processing. In 2017, the team built the world's first optical quantum computing prototype that surpassed early classical computers. In 2019, the team further developed the world's highest performance single-photon source with deterministic polarization, high purity, high homogeneity and high efficiency, realized Bose sampling of 20 photon input 60 mode interference lines, and the output Hilbert state spatial dimension reached 1014, approximating the "quantum computing superiority".
In 2020, Pan Jianwei's team successfully built the "Nine Chapters" of the 76 photon 100-mode Gaussian Bose sampling quantum computing prototype, the output quantum state space scale reached 1030, the speed of processing Gaussian Bose sampling was one hundred billion times faster than that of the supercomputer, and at the same time overcoming the loophole that quantum superiority depended on the sample size in Google's random line sampling experiment based on the "planewood" superconducting processor. After the completion of the "Nine Chapters" experiment, Professor Scott Aaronson, who theoretically proposed the Bose sampling algorithm and proved the computational complexity, subsequently received the ACM Prize in Computing from the International Computer Association.
In 2021, the team carried out a series of conceptual and technological innovations based on the "nine chapters". Inspired by the concept of laser-"stimulated radiant light amplification", researchers designed and implemented a stimulated bimodal quantum compression light source, which significantly improved the yield, quality and collection efficiency of the quantum light source. Second, through the compact design of three-dimensional integration and collection of optical paths, the multiphoton quantum interference circuit is increased to 144 dimensions. As a result, the number of photons detected by "Nine Chapters 2" increased to 113, and the spatial dimension of the output state reached 1043. Further, by dynamically adjusting the phase of the compressed light, the researchers achieved a reconfiguration of the Gaussian Bose sampling matrix, demonstrating the programming ability of The Nine Chapters II to solve mathematical problems with different parameters. According to the optimized classical algorithm that has been officially published, the "Nine Chapter Two" processing speed on the problem of Gaussian Bose sampling is hundreds of billions of times faster than that of the fastest supercomputer.
The researchers hope that this work will continue to inspire more work on classical algorithm simulations, and that there is room for improvement in the future. Quantum superiority experiments are not a one-time job, but a competition between faster classical algorithms and ever-improving quantum computing hardware, but in the end quantum parallelism will produce computing power that classical computers can't match.
Xin'an Evening News Anhui Network Dawan News reporter Chen Mu
Billions and billions of times faster than the fastest supercomputer!
It's really unconscious!
Thumbs up!
Source: CCTV News, Xin'an Evening News, Anhui Net, Dawan News