Development of quantum computing hardware - the intersection and collision of different physical systems | CQCC special forum

The implementation and performance improvement of quantum computing hardware are the key to restricting the practical application of quantum computing. Different physical systems such as superconductors, ion traps, neutral atoms, photons, and quantum dots each have their own advantages. This forum invited many experts to introduce different physical systems and discuss the frontiers and directions of future quantum computing hardware development.

Conference Introduction

The 1st CCF Quantum Computation Conference (CQCC 2022) will be held in the "Green City" Zhengzhou on August 20-21, 2022. Professor Guo Guangcan, director of the CCF Quantum Computing Professional Group and academician of the Chinese Academy of Sciences, served as the chairman of the conference. Professor Lu Lu, Academician of the Chinese Academy of Engineering, Researcher Ying Mingsheng of the Institute of Software, Chinese Academy of Sciences, Professor Ding Jintai of the Yau Chengtong Mathematics Center of Tsinghua University, Professor Shan Zheng of the University of Information Engineering, Professor Duan Luming of Tsinghua University, Professor Yu Yang of Nanjing University, and Zhao Yong, Vice President of Hefei Origin Quantum Computing Technology Co., Ltd. General Jie will give a special report at the conference, and experts and scholars such as Academician Zheng Jianhua of the Chinese Academy of Sciences will also attend the conference.

Forum background

In recent years, quantum computing has received great attention from governments, the scientific community, and the industry at home and abroad. The vigorous development of quantum computing hardware has directly led to the verification of quantum advantage algorithms and promoted the development of various practical applications of quantum computing, marking that quantum computing has entered a new stage of development. The next key to the development of quantum computing hardware is how to solve the problem of system scalability while maintaining and improving system performance. Different physical systems have different characteristics and advantages when implementing quantum computing hardware, and the difficulties they encounter are also different. This forum invited a number of heavyweight and authoritative scholars in the field of quantum computing in my country to introduce cutting-edge work on different physical systems such as superconductors, ion traps, neutral atoms, photons, and quantum dots, and discuss future development trends and technologies. It is hoped that through the intersection of different physical systems, new sparks will be created for the development of quantum computing hardware.

Time, place and method of participation (conference number or live broadcast link)

time and location

First half : August 20, 14:00-18:00; Triumph Hall, Guanghua Hotel, Zhengzhou & online
Second half : August 21, 14:00-18:00; Saturn Hall, Guanghua Hotel, Zhengzhou & online

*Note: (The live link will be sent to the registered participants’ email address before the meeting)

Forum Schedule

First half report and guest introduction

Report 1

Chen Pingxing , professor and doctoral supervisor at the National University of Defense Technology, director of the Hunan Provincial Key Laboratory of "Quantum Information Mechanism and Technology". He has long been engaged in research on the basic theory of quantum information, quantum simulation and quantum computing based on trapped ions. He has published more than 100 SCI academic papers in famous domestic and foreign journals and 3 academic books. As the first completer, he won 1 First Prize of Hunan Provincial Natural Science Award, and as the main completer, he won 2 military and provincial and ministerial level science and technology awards. Vice Chairman of the Quantum Communication Committee of the China Communications Society, member of the Quantum Optics Professional Committee of the Chinese Physical Society, and editorial board member of Journal of Quantum Optics and Journal of Quantum Electronics.

Report title : Analysis of trapped ion technology for quantum simulation

Report summary : In order to achieve high-precision and large-scale quantum simulation, noise suppression, deep cooling and scale expansion of trapped ions are important technical problems. We conducted an in-depth analysis of various noises in which ions are exposed, and carried out effective suppression. We proposed and verified a multi-ion deep cooling scheme, which effectively improved the bit control accuracy. An ion chip trap based on micro-nano processing was developed, and the transport, separation and merger of ions were realized in the chip trap. A new generation of high-performance chip trap was also developed. Some meaningful quantum simulations have also been implemented on ion platforms.

Report 2

Kihwan Kim（金奇奂） received BS, MS, and Ph.D at the Department of Physics of Seoul National University. He did post-docs at the Innsbruck University and University of Maryland. He joined Tsinghua University in 2011 and is a full professor currently. After joining Tsinghua University, Prof. Kim has contacted experimental research for the trapped ion quantum computation. He has published over 70 SCI papers, which are cited more than 6,500 citations (data from Google Scholar 2022/07), which includes Nature, Nature Photonics, Nature Physics, Nature Communications, Physical Review X, Physical Review Letters, etc.

Report title : Trapped-ion technology for the large-scale quantum computation.

报告摘要 ：In this talk, we discuss two directions of scaling up the trapped-ion system for quantum computation and quantum simulation. The first one is to use vibrational degrees of freedom in a linear chain of ions and the second one is to use internal degrees of freedom in the 2D crystals of ions. We also discuss the method to speed up the entangling gate operation, which is necessary for the quantum computation.

Report three

Zhang Jieying , who graduated with a Ph.D. from the University of Maryland, worked on laser cooling and precision spectroscopy measurements of radioactive atoms at Canada's TRIUMF National Laboratory. Postdoctoral fellow under Professor Christopher Monroe of the University of Maryland (now Duke University), he studied quantum simulation based on ion trap systems, successfully realized discrete time crystals, and studied quantum non-equilibrium phase transitions that are difficult to simulate with classical computers. Articles have been published in Nature magazine superior. Dr. Zhang Jiexie has been an assistant professor in the Department of Physics at New York University since January 2019. He will return to China full-time in December 2021 and work at the Shanghai Research Institute of the University of Science and Technology of China.

Report title : Some new progress in ion quantum information processing: cooling beyond the LD limit and non-Euclidean geometry coding

Report summary : Ion traps are one of the leading platforms for quantum computing. I will introduce some new experimental advances in ion trap quantum information processing: using one-dimensional beryllium ions to achieve ground state cooling beyond the Lamb-Dicke limit, and realizing quantum bit encoding in an equivalent high-dimensional space, fully demonstrating the full connectivity advantage of ion systems. The combination of high-fidelity operations and high connectivity will become the key to future ion trap quantum computing beyond the classical limit.

Report 4

Lin Yiheng is a professor in the Department of Modern Physics, School of Physics, University of Science and Technology of China. Research work mainly focuses on experimental research on ion trap quantum information processing, covering cutting-edge topics such as quantum gates, new quantum entanglement, collaborative cooling, and dissipative quantum systems. Published many papers on quantum information processing.

Report title : Quantum simulation and quantum information processing of multi-level ion trap systems

Report Abstract : In recent years, rapid progress has been made in quantum control and demonstration of new applications of multi-level quantum systems. We have bound Be+ ions, combining electron and nuclear spins, as an experimental platform for multiple ground state energy levels. We separated three energy levels to demonstrate multi-level coherence protection, increasing the quantum state coherence time by an order of magnitude; we also designed a three-level Hamiltonian to simulate the momentum space system and observed the topological phase transition of the triple degenerate point induced by the spin tensor. In addition, we demonstrated analytically assisted shaped pulses to achieve fast and complete control between two adjacent transitions of a four-level system, alleviating the spectral crowding problem of multi-level systems. We hope that these experiments will help further explore the quantum applications of multi-level systems.

Report 5

Wang Zhao is an assistant researcher at the Institute of Quantum Science and Engineering of Southern University of Science and Technology. He received his Ph.D. from the Key Laboratory of Quantum Information of the Chinese Academy of Sciences at the University of Science and Technology of China. He is mainly engaged in research on quantum computing and scalable quantum chips based on ion trap systems. He has published many SCI papers in domestic and foreign journals such as Sci. Bull. and PRL, applied for 6 national and international invention patents, obtained funding from the National and Guangdong Provincial Natural Science Youth and General Funds, and participated in the Guangdong Provincial Key Field R&D Plan.

Report title : Scalable chip ion trap technology and progress

Report summary : Trapped ion systems are currently one of the most promising physical systems for realizing universal quantum computing. A series of exploration and verification of physical characteristics and system advantages have been carried out using macroscopic ion trap devices with a small number of electrodes, and a quantum computing prototype of tens of bits has been demonstrated. However, the problem of how to further increase the number of high-fidelity ion bits and improve system stability and integration seriously restricts the expansion and scale of the system. Chip-type ion trap is currently an important method to solve the scalability problem of this system. Through micromachining technology, complex and numerous electrode structures can be prepared in a standardized manner, and multiple devices such as light, electricity, and detectors can be integrated on-chip at the same time. In this report, we will briefly introduce the development trends, technical difficulties and some progress we have made in ion trap chips.

Report 6

Zhang Xiang received his PhD from Tsinghua University in 2016 and has been an associate professor in the Department of Physics at Renmin University of China since 2019. He has been engaged in quantum experimental research based on trapped ions for a long time and published 20 SCI papers, of which the first or corresponding author published 4 papers in Nat. Comm. and PRL. Selected into the first batch of the national "Postdoctoral Innovative Talent Support Program", he presided over the National Natural Science Foundation's youth projects, general projects, major research plan cultivation projects, Beijing Natural Science Foundation key research and development projects, etc.

Report title : Research on quantum control based on trapped ions

Report summary : There are many problems that need to be solved in current quantum control research of high-dimensional systems. The report will introduce and share some of our efforts in the direction of quantum control research in order to realize a fully programmable multi-bit ion quantum computer, including the construction of a modular transportable multi-ion experimental platform and the design of a fully digital integrated experimental control system. and development, design, implementation and application of new quantum state manipulation schemes, etc. We have also promoted the application of microscopic methods of quantum control in cutting-edge scientific research such as quantum field theory and quantum chemistry. We have used controllable quantum systems to perform complex computing tasks, demonstrating the potential to surpass classical computing capabilities.

Report 7

Xu Peng is a researcher at the Institute of Precision Measurement Science and Technology Innovation, Chinese Academy of Sciences. He graduated with a doctorate from the Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences. During his work, he went to the University of Bonn in Germany to conduct short-term collaborative research. Engaged in quantum simulation and quantum computing based on single atoms and atomic arrays in optical tweezers, he has published more than 30 SCI papers in Science, PRL, Nat. Commun., etc., and as the project leader has undertaken many national key research and development projects, etc. National project.

Report title : Progress in quantum computing of neutral atoms

Report summary : The report will introduce the research conducted by our team around a series of key problems in neutral atom quantum computing, including the realization and fidelity improvement of two-atom quantum controlled NOT gate, the complete control of atomic internal and external states and the breakthrough of coherence time, and the realization of defect-free heteronuclear multi-atom arrays. Finally, the report will combine the latest progress of atomic systems at home and abroad to look forward to the opportunities and challenges faced by this system in the direction of quantum computing.

Second half report and guest introduction

Report Eight

Wu Junjie , Ph.D., researcher, doctoral supervisor, currently serves as director of the Institute of Quantum Information and the State Key Laboratory of High Performance Computing at the School of Computer Science, National University of Defense Technology. Distinguished member of the China Computer Federation (CCF), standing member of the CCF Quantum Information Professional Group, secretary-general of the CCF Architecture Professional Committee (2011-2019), member of the Quantum Information Branch of the China Electronics Society, and member of the National Technical Committee for Quantum Computing and Measurement Standardization. Engaged in research in the direction of quantum computing, he presided over the successful development of the Galaxy Kunteng QW2020 quantum computing system, QUANTA VQS16 quantum computing system, etc. His research results on quantum hegemony standards, optical quantum chips, etc. have been published in domestic and foreign technology media such as Science and Technology Daily. He published papers in Science Advances, National Science Review, Physical Review Letters, etc., and won the first prize of Hunan Province Natural Science Award.

Report title : Large-scale full-programmable quantum walk and its applications

Report Summary : Quantum computing is an important post-Moore computing technology that is expected to bring revolutionary computing power improvements. In recent years, the physical implementation technology of quantum computing has developed rapidly, and has reached the computing power level of quantum supremacy in benchmark problems such as random quantum circuit sampling and Gaussian boson sampling. Based on the current noisy quantum bits, how to develop dedicated quantum computing for practical problems is one of the research goals pursued internationally. Quantum walk can be regarded as a computing model that can be used to design and develop quantum algorithms. This report will introduce our practice and exploration in building a quantum walk optical quantum system.

Report Nine

Xu Jinshi is a professor and doctoral supervisor at the University of Science and Technology of China, and a recipient of the National Outstanding Young Scientist Fund. He is mainly engaged in experimental research on quantum information and quantum physics based on light and solid-state spin systems, and has published more than 100 papers in academic journals such as Nature, Science, and Physical Review Letters. He has won the National 100 Outstanding Doctoral Dissertation Award, the Wang Daheng Optics Award for Young and Middle-aged Scientific and Technological Personnel, and the Second Prize of the National Natural Science Award. He is currently the Secretary-General of the Optical Quantum Science and Technology Professional Committee of the Chinese Optical Society, a young editorial board member of the China Laser Magazine, and an editorial board member of the Journal of Optics.

Report title : Quantum photonic simulation for high-dimensional multi-mode

Report summary : Quantum simulation is to simulate the properties and evolution of another complex system with a controllable quantum system. Linear optical systems can effectively shield the influence of the environment on the system, and can easily realize the encoding and operation of high-dimensional multi-modes. They are important systems in the field of quantum information research. This report will introduce some of our experimental progress in realizing light quantum simulation based on linear optical systems. We develop encoding and operation methods for multi-spatial modes of photons, simulate the statistical properties of the zero mode of quasi-fermions and study their quantum intertextual properties, and demonstrate a fault-tolerant quantum computing architecture based on the zero mode of quasi-fermions. On the other hand, the artificial synthetic dimension constructed using the intrinsic degrees of freedom of photons provides an effective means to study the properties of high-dimensional systems. We built an orbital angular momentum degenerate optical cavity to bind multiple spatial modes to construct optical artificial dimensions, and realized direct detection based on the topological energy spectrum properties of the degenerate cavity.

Report ten

Cao Gang is a professor and doctoral supervisor at the Key Laboratory of Quantum Information of the Chinese Academy of Sciences at the University of Science and Technology of China. Mainly engaged in semiconductor quantum computing and quantum transport research. He has published more than 80 papers in domestic and foreign journals such as Nature Communications, Science Advances, Physical Review Letters, and Science Bulletin. Received funding from the National Natural Science Foundation of China's Excellent, General and Youth Funds, etc.; is the project leader of the Quantum Communication and Quantum Computer Guidance Project of Anhui Province; and has participated in many national projects such as the National Key R&D Program and the 973 Program as an academic backbone. Won the first prize of Anhui Provincial Natural Science Award in 2018 (2/5).

Report title : Gate-controlled semiconductor quantum computing

Report summary : Semiconductor gate-controlled quantum dots have good scalability and integration characteristics. At the same time, their preparation process is compatible with modern semiconductor processes. Quantum computing solutions based on semiconductor gate-controlled quantum dots have attracted much attention from all walks of life. Intel, CEA-Leti, IMEC, etc. have begun to use production line processes to participate in the research of semiconductor quantum computing. In recent years, with the advancement and development of technology, semiconductor systems have made a series of breakthroughs in quantum gate control and bit expansion. The report will focus on this system, introduce the basic principles of quantum dots, quantum bit encoding methods and control and measurement processes, and briefly describe the development of semiconductor quantum computing. Finally, the report will also give a brief outlook on the future development trend of semiconductor quantum computing.

Report 11

Xiang Zhongcheng received his Ph.D. in Science from Beihang University in July 2019 (jointly trained with the Institute of Physics, Chinese Academy of Sciences). He worked as a postdoctoral fellow at the Institute of Physics, Chinese Academy of Sciences, and was selected as a "key technical talent" among the talents introduced by the Institute of Physics, Chinese Academy of Sciences in 2021. He is mainly engaged in the design, preparation and application research of superconducting quantum devices. He has accumulated a lot of professional knowledge and experience in the design and preparation of superconducting quantum circuits. He has designed and prepared high-quality multi-bit quantum chips of various configurations, including one-dimensional (43 bits), ladder-type (30 bits), adjustable coupling samples, etc., as well as a high-gain, wide-bandwidth Josephson parametric amplifier (JPA), in which the decoherence time of the quantum bit (double-junction squid) can reach a good level of 100 microseconds. The designed and prepared quantum chips with different functions have stable parameters, providing satisfactory samples for many domestic units and have successfully used these devices for a number of quantum experiments.

Report title : Progress in Quantum Chip Preparation

Report summary : In recent years, the design and preparation of superconducting quantum bit chips have developed rapidly, and both the number of bits and the quality of chips have been greatly improved. The Institute of Physics has accumulated many years of experience and deep understanding in the field of superconducting quantum computing. Especially since the advent of the Transmon bit, we have designed and prepared high-quality multi-bit quantum chips of various configurations, including one-dimensional 5-bit chips, 10-bit chips, adjustable coupling quantum chips, 30-bit ladder chips, 43-bit chips, and a high-gain, wide-bandwidth Josephson parametric amplifier (JPA), in which the decoherence time of the quantum bit (double-junction squid) can reach a good level of 100 microseconds. The parameters of the quantum chips with different functions designed and prepared are stable, providing satisfactory samples for many domestic units and successfully using these devices for a number of quantum experiments.

Speaker 12

Yan Fei is an associate researcher at the Shenzhen Institute of Quantum Science and Engineering of Southern University of Science and Technology. He graduated from Nanjing University with a bachelor's degree and a Ph.D. from the Massachusetts Institute of Technology. He has been engaged in research on superconducting quantum computing experiments for a long time. His main research interests include: quantum chip architecture design, quantum control, noise and decoherence, quantum error correction, etc.

Report title : Research on Scalability of Superconducting Quantum Information Processors

报告摘要 ：Scalability of quantum information processing is a complex concept that involves both hardware and software performance, both width and depth of the quantum circuit, both long-term potential and near-term feasibility. In this talk, I will discuss how we think about building a scalable quantum processor with superconducting qubits, focusing on a novel architecture based on tunable coupler which enables fast, accurate quantum operations. Based on the same architecture, we also successfully implement a quantum version of AND logic which enables efficient circuit decomposition of complex operations.

Speaker Thirteen

Youpeng Zhong received his bachelor's degree from Zhejiang University in 2013 and his doctorate from the Pritzker School of Molecular Engineering at the University of Chicago in 2019, under the tutelage of Professor Andrew N. Cleland. He stayed in Cleland's group from 2019 to 2020 to continue his postdoctoral research. In November 2020, he joined the Institute of Quantum Science and Engineering at Southern University of Science and Technology, focusing on superconducting quantum computing. In 2021, he received support from the National High-level Talent Overseas Youth Project and Shenzhen National Leading Talent Program. So far, he has published 24 SCI papers, including 3 Nature and Science; 5 of them are first-authored, including 1 Nature, 1 Nature Physics, 1 Nature Communications, and 2 PRL.

Report title : Scalable distributed superconducting quantum computing

Report summary : Distributed quantum computing expands superconducting quantum computers through the interconnection of multiple quantum chips. This broken-down approach can greatly reduce the difficulty of integration, but requires ultra-low-loss channels to connect quantum chips to avoid decoherence. . Recently, we have made some experimental progress in this direction. We connected two superconducting quantum chips through a niobium-titanium superconducting coaxial line, achieving low-loss quantum chip interconnection and high-fidelity quantum state transmission between chips. On this basis, we prepared a 3-bit GHZ entangled state on one chip and deterministically transmitted it to another chip in a serial manner. Finally, we successfully prepared a globally distributed 6-bit GHZ entangled state. These technologies lay the foundation for building scalable distributed superconducting quantum computers.

Forum Chairman

Wang Zhao is an assistant researcher at the Institute of Quantum Science and Engineering of Southern University of Science and Technology. He received his Ph.D. from the Key Laboratory of Quantum Information of the Chinese Academy of Sciences at the University of Science and Technology of China. He is mainly engaged in research on quantum computing and scalable quantum chips based on ion trap systems. He has published many SCI papers in domestic and foreign journals such as Sci. Bull. and PRL, applied for 6 national and international invention patents, obtained funding from the National and Guangdong Provincial Natural Science Youth and General Funds, and participated in the Guangdong Provincial Key Field R&D Plan.

Wang Weilong , Ph.D., is a lecturer at the University of Information Engineering. Mainly engaged in research on quantum cryptography and quantum computing. His research results in quantum communication, quantum cryptography, superconducting quantum chip design, etc. have been published in more than 20 papers in domestic and foreign journals such as Physical Review Letters, New Journal of Physics, and Laser Physics Letters. , as an academic backbone, participated in the research work of many scientific research projects such as the National 863 Plan, the 173 Plan, and the National Natural Foundation of China.

For details on online participation in the above forums (registration required), please visit the official website of the conference. In addition to the invited reports and this forum, the first CCF Quantum Computing Conference also has 9 special forums covering software and hardware, industry, education and other fields, and has a sharing session on outstanding papers/representative work.

At present, the preparations for the conference are nearing completion. We welcome scholars in the fields of computing, physics, etc. who are interested in quantum computing to come to the "Green City" Zhengzhou to participate in the first CCF Quantum Computing Conference to exchange academic ideas, explore cooperation, and jointly witness and promote the development of my country's quantum computing industry.

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