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Jiuzhang (quantum Computer)
Jiuzhang ( zh, 九章) is the first photonic quantum computer to claim quantum supremacy. Previously quantum supremacy has been achieved only once in 2019 by Google’s Sycamore processor, Sycamore, however Google's computer was based on superconducting materials, and not photons. Jiuzhang was developed by a team from University of Science and Technology of China (USTC) led by Pan Jianwei and Lu Chaoyang. The computer is named after ''Jiuzhang suanshu'', an ancient Chinese mathematical classic. On 3 December 2020, USTC announced in ''Science (journal), Science'' that Jiuzhang successfully performed Gaussian boson sampling in 200 seconds, with a maximum of 76 detected photons. The USTC group estimated that it would take 2.5 billion years for the Sunway TaihuLight supercomputer to perform the same calculation. In addition to a quantum computational advantage, Jiuzhang has a Hilbert space 10 billion times larger than Google's superconductor-based Sycamore processor, and as such, is har ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quantum Computer
Quantum computing is a type of computation whose operations can harness the phenomena of quantum mechanics, such as superposition, interference, and entanglement. Devices that perform quantum computations are known as quantum computers. Though current quantum computers may be too small to outperform usual (classical) computers for practical applications, larger realizations are believed to be capable of solving certain computational problems, such as integer factorization (which underlies RSA encryption), substantially faster than classical computers. The study of quantum computing is a subfield of quantum information science. There are several models of quantum computation with the most widely used being quantum circuits. Other models include the quantum Turing machine, quantum annealing, and adiabatic quantum computation. Most models are based on the quantum bit, or "qubit", which is somewhat analogous to the bit in classical computation. A qubit can be in a 1 or 0 quantum ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hilbert Space
In mathematics, Hilbert spaces (named after David Hilbert) allow generalizing the methods of linear algebra and calculus from (finite-dimensional) Euclidean vector spaces to spaces that may be infinite-dimensional. Hilbert spaces arise naturally and frequently in mathematics and physics, typically as function spaces. Formally, a Hilbert space is a vector space equipped with an inner product that defines a distance function for which the space is a complete metric space. The earliest Hilbert spaces were studied from this point of view in the first decade of the 20th century by David Hilbert, Erhard Schmidt, and Frigyes Riesz. They are indispensable tools in the theories of partial differential equations, quantum mechanics, Fourier analysis (which includes applications to signal processing and heat transfer), and ergodic theory (which forms the mathematical underpinning of thermodynamics). John von Neumann coined the term ''Hilbert space'' for the abstract concept that under ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
2020 In Science
A number of significant scientific events occurred in 2020. Events January February March April May June July August September October * 1 October ** Researchers report the discovery of a novel overlapping gene (OLG) (a gene partially overlapping with a sequence of another gene), named ''ORF3d'', in the SARS-CoV-2 genome, that may be a factor in the SARS-CoV-2 pandemic. They found the gene has been identified before, but only in a variant of coronavirus that infects pangolins. Available undeCC BY 4.0 **Astronomers announce spectroscopic confirmation of a web-like structure containing galaxies and dark matter around, and likely fueling, a quasar at an age of the Universe of 0.9 bn years, which contributes to an explanation of how such supermassive black holes could have grown rapidly so early. * 2 October – A rippling graphene-based Brownian ratchet-related energy-harvesting circuit with the potential to deliver "clean, limitless, low-voltage power fo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Single-photon Detector
Photon counting is a technique in which individual photons are counted using a single-photon detector (SPD). A single-photon detector emits a pulse of signal for each detected photon, in contrast to a normal photodetector, which generates an analog signal proportional to the photon flux. The number of pulses (but not their amplitude) is counted, giving an integer number of photons detected per measurement interval. The counting efficiency is determined by the quantum efficiency and the system's electronic losses. Many photodetector Photodetectors, also called photosensors, are sensors of light or other electromagnetic radiation. There is a wide variety of photodetectors which may be classified by mechanism of detection, such as Photoelectric effect, photoelectric or photoc ...s can be configured to detect individual photons, each with relative advantages and disadvantages. Common types include photomultipliers, geiger counters, single-photon avalanche diodes, superconducting na ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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