Due to its strong computing power and wide application prospects, quantum technology is regarded as "the technology that determines the future".
Chapter IX No. 2
Recently, the famous physics journal "Physical Review Letters" published two papers from the University of Science and Technology of China at the same time. The article shows that the two quantum computers developed by Pan Jianwei's team were successfully upgraded to "Zu Chong No. 2" and "Jiuzhang No. 2". This means that China has become the only country in the world to reach the milestone of quantum computing superiority in two physical systems, which can be described as "double happiness".
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Zu Chong No. 2
For specific issues
Quantum computing hashing power
What is the significance of upgrading the "Zu Chong No" and "Nine Chapters" to version 2.0? Before answering this question, we must first understand what quantum computing is. Essentially, quantum computing is a new principle of computing that, through specific algorithms, can produce more computing power than classical computers. Japan's supercomputer Fugaku is currently the world's most powerful classical computer, running 4.42 billion billion floating-point operations per second. Even if its computing power is not to be underestimated, it is still dwarfed by quantum computers. In the case of the optical quantum computer "Nine Chapter Two", it is a billion billion billion times faster than a supercomputer (10 to the power of 24 times) in the calculation of a particular problem. The "power" of quantum computing can be seen. However, quantum computers will not completely replace classical computers. Because quantum computers only surpass classical computers in terms of computation speed for certain specific problems, not all problems. For example, the optical quantum computer "Nine Chapters" is only used to calculate Gaussian Bose sampling; the superconducting quantum computer "Zu Chong Zhi" is used to deal with quantum random line sampling problems.
It is understood that these are also the two solutions that can best demonstrate the superiority of quantum computing. Quantum computing superiority refers to the processing of a particular problem, and quantum computers surpass the strongest classical computers.
But achieving the superiority of quantum computing is not an easy task. The super computing power of quantum computers is inseparable from its special data storage method - qubits. The more qubits a quantum computer can manipulate with high precision, the faster it can process a particular problem. The quantum state (the constant motion of electrons) is fragile and sensitive, and is highly susceptible to the noise of the surrounding environment. For quantum computers, whether it is increasing the number of integrated qubits or improving the fidelity of manipulation, it is a serious challenge.
Two physical systems
Achieve the superiority of quantum computing
With the advancement of technology and theory, quantum computing has continued to make important progress in recent years.
Recently, Pan Jianwei's team upgraded Jiuzhang and Zu Chongzhi to version 2.0, making China the only country in the world to achieve quantum computing superiority in two physical systems, superconductivity and optics. The physical system can be simply understood as a technical route. There are many technical routes to achieve quantum computers, including superconducting qubits, optics, ultracold atoms, ion traps, semiconductor quantum dots, and so on. Because of their unique advantages, superconducting qubits and optics "stand out" among many physical systems. In the superconducting qubit system, in 2019, Google built a 53-bit superconducting quantum computing prototype "planewood" to achieve the superiority of quantum computing.
In terms of optical system, in 2020, Pan Jianwei's team built a 76-photon quantum computing prototype "Nine Chapters", making China the second country in the world to realize the superiority of quantum computing. In May of the same year, Pan Jianwei's team also built a 62-bit "Zu Chong No." It is the same as the "plane wood" superconducting quantum computer, because the control is not good enough, and does not achieve the superiority of quantum computing. So, compared with before the upgrade, what is the breakthrough of "Nine Chapters Ii" and "Zu Chong No. 2"? Among them, the computing power of "Nine Chapters and Two" has achieved a huge improvement. It deals with Gaussian bose sampling problems 10 billion times faster than the "nine chapters".
For the first time, "Zuchong-2" achieved the superiority of quantum computing. In the handling of random line sampling problems, it is 7 orders of magnitude faster than the fastest supercomputer "Fugaku", and in terms of computational complexity, it is 6 orders of magnitude faster than "plane wood". It can be said that at present, China's quantum computing research is leading the world.
Three goals of quantum computers
Great application potential
Cutting-edge technology for the future
Although quantum computing is in full swing, we have not yet built any quantum computers with practical value.
The well-known quantum computers such as "PlaneWood", "Jiuzhang Ii" and "Zu Chong No. 2" are only prototypes that stay in the laboratory stage. So, what is the significance of achieving the superiority of quantum computing? The development of quantum computing cannot be achieved overnight. First of all, it is necessary to coherently manipulate more than 50 qubits to achieve the superiority of quantum computing; second, it is necessary to coherently manipulate hundreds to thousands of qubits to make a practical quantum simulator; finally, coherently manipulate millions of qubits to make a general-purpose quantum computer.
The realization of the superiority of quantum computing marks that the development of quantum computing will enter the second stage and is expected to be applied to specific fields. For example, "Zu Chong No. 2" adopts a new flip-soldering 3D packaging process to solve the problem of large-scale bit integration, and realizes the high-density integration of 66 data bits, 110 coupling bits, and 11 reads. Its parallel high-fidelity metric subgate manipulation capabilities and fully programmable capabilities are expected to be applied to quantum machine learning, quantum approximation optimization and other fields. The super computing power of "Nine Chapter Two" also has potential application value in the fields of graph theory and quantum chemistry, and is expected to play a role in code breaking, weather forecasting, material design, drug analysis and other fields in the future.