Pan Jianwei, Lu Chaoyang, of the University of Science and Technology of China, in cooperation with Yu Lixing of the Shanghai Institute of Microsystems and Information Technology of the Chinese Academy of Sciences and scientists from Germany and the Netherlands, have achieved the first time in the world the poracal sampling quantum computation of 20 photon input 60 x 60 mode interference lines, and output the Hilbert state space with a complexity equivalent to 48 qubits. , its dimensions are as high as 370 trillion.
This work also greatly exceeds the previous international records in the four key indicators of photon number, pattern number, computational complexity, and state space, in which the state space dimension is ten billion times higher than the previous optical quantum computing experiments of international peers. The paper was published in Physical Review Letters in the form of an “editor’s recommendation”. The Physics website of the American Physical Society features a feature on this work under the title “The Near milestone of boson sampling quantum computing”.
Quantum computers have ultra-fast parallel computing power in principle, and they achieve exponential acceleration compared to classical computers in some problems of great social and economic value. At present, the development of quantum computer has become one of the biggest challenges of cutting-edge science, and has become the focus of competition in all countries in the world. Among them, the first stage goal of quantum computing research is to realize the “superiority of quantum computing” (also known as “quantum supremacy”), that is, to develop a prototype of quantum computing to surpass the classical supercomputer in solving a particular task. The use of superconducting qubits to achieve random line sampling and the use of photons to achieve boson sampling is currently recognized in international academic circles to demonstrate the superiority of quantum computing two major ways.
Facing this strategic goal, Pan Jianwei and Lu Chaoyang Research Group have long been committed to the research of scalable single photon sources and boson sampling quantum computing. In 2013, the research team pioneered quantum dot pulse resonance stimulation in the world, solving the two basic problems of certainty and high quality of single photon sources. In 2016, the research team developed a single quantum dot device with precise coupling of microcavities, resulting in the highest international efficiency of the same single photon source, and on this basis, in 2017 was initially used to build a optical quantum computing prototype that transcends the early classical computing power for boson sampling. The sampling rate was more than 24,000 times higher than the international experiments at the time.
In 2019, the team proposed coherent two-color excitation (Nature Physics 15, 941 (2019)) and elliptical microcavity coupling (Photonics 13, 770 (2019)) In the experiment, the two final problems of mixed polarization and laser background scattering existing in single photon sources were solved, and a single photon source of deterministic polarization, high purity, high all-homogenous and high efficiency was successfully developed in narrow band and broadband microcavity, and the relevant results were selected as the cover article of Nature Photonics. Professor Reimer, of the University of Waterloo, Canada, commented on the results under the title “The quest for a perfect-single-photon source”, noting: “Previously, the international search for the perfect single-photon device had lasted for two decades, However, these three indicators have never been implemented at the same time (in the search for a perfect single-photon device, who hass seachover over two decades, all three severing c Riteria have not yet yet justly ly bemet), “this ground-breaking study is a milestone achievement for the perfect single photon source (groundbreaking research reporting a milflash ac Hievement cyns this ideality goal with the tha a single-photon source” .
The research team of China University of Science and Technology has successfully achieved 20 photon inputs of 60 x through cooperation with Yu Lixing of the Shanghai Institute of Microsystems and Information Technology of the Chinese Academy of Sciences in the field of superconducting nanowire high-efficiency single photon detectors, using the international highest efficiency and highest quality single photon source, maximum scale and maximum transmission rate of multi-channel optical interferometers. The 60 mode (60 inputs, 60 layers of line depth, including 396 beam dividers and 108 mirrors) interfered with the bose sampling experiment of the line. Compared to similar work by international peers at research institutions such as Oxford University, the University of Vienna, the French National Academy of Sciences, the University of Bristol, the University of Queensland, the University of Rome, the Massachusetts Institute of Technology and the University of Maryland, the number of monophotons successfully manipulated increased fivefold, the number of models increased fivefold, and the sampling rate increased by 60,000. The output state space dimension has increased by ten billion times. Among them, due to the high-mode characteristics of multi-photons, the output state space reached 370 trillion dimensions, which is equivalent to the 48 qubits of the expanded Hilbert space. As a result, the experiment advanced the boson sampling to a whole new area for the first time: the inability to directly and fully validate the wave-color sampling quantum computing prototype through a classic computer, a crucial step toward demonstrating the scientific goal of demonstrating the superiority of quantum computing.
The reviewer noted that the work was “an important step in solving key issues” and was an “impressive technical achievement” “A great leap”, “not only an influential test of the quantum computing power of light, but also a spring springboard for the superiority of quantum computing. powerful test of photonic strength but, rather, a trampoline for the upcoming quantum supremacy). “This represents a milestone in quantum computing: approaching the point where a classic computer cannot simulate a quantum system, ” says a summary of the work on the Physics Website of the American Physical Society. computation: approaching the point where a classical system cannot glygly a quantum system”.
The research work has been supported by the Natural Science Foundation of China, the Ministry of Science and Technology, the Chinese Academy of Sciences, the Ministry of Education, Anhui Province, The Shanghai Science and Technology Commission and other units.