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Quantum Volume
Quantum volume is a metric that measures the capabilities and error rates of a quantum computer. It expresses the maximum size of square quantum circuits that can be implemented successfully by the computer. The form of the circuits is independent from the quantum computer architecture, but compiler can transform and optimize it to take advantage of the computer's features. Thus, quantum volumes for different architectures can be compared. Introduction Quantum computers are difficult to compare. Quantum volume is a single number designed to show all around performance. It is a measurement and not a calculation, and takes into account several features of a quantum computer, starting with its number of qubits—other measures used are gate and measurement errors, crosstalk and connectivity. IBM defined its Quantum Volume metric because a classical computer's transistor count and a quantum computer's quantum bit count aren't the same. Qubits decohere with a resulting loss of performan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quantum Computing
A quantum computer is a computer that exploits quantum mechanical phenomena. On small scales, physical matter exhibits properties of wave-particle duality, both particles and waves, and quantum computing takes advantage of this behavior using specialized hardware. Classical physics cannot explain the operation of these quantum devices, and a scalable quantum computer could perform some calculations Exponential growth, exponentially faster than any modern "classical" computer. Theoretically a large-scale quantum computer could post-quantum cryptography, break some widely used encryption schemes and aid physicists in performing quantum simulator, physical simulations; however, the current state of the art is largely experimental and impractical, with several obstacles to useful applications. The basic unit of information in quantum computing, the qubit (or "quantum bit"), serves the same function as the bit in classical computing. However, unlike a classical bit, which can be in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quantum Logic Gate
In quantum computing and specifically the quantum circuit model of computation, a quantum logic gate (or simply quantum gate) is a basic quantum circuit operating on a small number of qubits. Quantum logic gates are the building blocks of quantum circuits, like classical logic gates are for conventional digital circuits. Unlike many classical logic gates, quantum logic gates are reversible. It is possible to perform classical computing using only reversible gates. For example, the reversible Toffoli gate can implement all Boolean functions, often at the cost of having to use ancilla bits. The Toffoli gate has a direct quantum equivalent, showing that quantum circuits can perform all operations performed by classical circuits. Quantum gates are unitary operators, and are described as unitary matrices relative to some orthonormal basis. Usually the ''computational basis'' is used, which unless comparing it with something, just means that for a ''d''-level quantum system ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quantum Fidelity
In quantum mechanics, notably in quantum information theory, fidelity quantifies the "closeness" between two density matrices. It expresses the probability that one state will pass a test to identify as the other. It is not a metric on the space of density matrices, but it can be used to define the Bures metric on this space. Definition The fidelity between two quantum states ''\rho'' and ''\sigma'', expressed as density matrices, is commonly defined as:R. Jozsa, ''Fidelity for Mixed Quantum States'', J. Mod. Opt. 41, 2315--2323 (1994). DOI: http://doi.org/10.1080/09500349414552171 :F(\rho, \sigma) = \left(\operatorname \sqrt\right)^2. The square roots in this expression are well-defined because both \rho and \sqrt\rho\sigma\sqrt\rho are positive semidefinite matrices, and the square root of a positive semidefinite matrix is defined via the spectral theorem. The Euclidean inner product from the classical definition is replaced by the Hilbert–Schmidt inner product. As will ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Noisy Intermediate-scale Quantum Era
The current state of quantum computing is referred to as the noisy intermediate-scale quantum (NISQ) era, characterized by quantum processors containing up to 1,000 qubits which are not advanced enough yet for fault-tolerance or large enough to achieve quantum advantage. These processors, which are sensitive to their environment (noisy) and prone to quantum decoherence, are not yet capable of continuous quantum error correction. This intermediate-scale is defined by the quantum volume, which is based on the moderate number of qubits and gate fidelity. The term NISQ was coined by John Preskill in 2018. According to Microsoft Azure Quantum's scheme, NISQ computation is considered level 1, the lowest of the quantum computing implementation levels. In October 2023, the 1,000 qubit mark was passed for the first time by Atom Computing's 1,180 qubit quantum processor. However, as of 2024, only two quantum processors have over 1,000 qubits, with sub-1,000 quantum processors still rem ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pareto Front
In multi-objective optimization, the Pareto front (also called Pareto frontier or Pareto curve) is the set of all Pareto efficient solutions. The concept is widely used in engineering. It allows the designer to restrict attention to the set of efficient choices, and to make tradeoffs within this set, rather than considering the full range of every parameter. Definition The Pareto frontier, ''P''(''Y''), may be more formally described as follows. Consider a system with function f: X \rightarrow \mathbb^m, where ''X'' is a compact set of feasible decisions in the metric space \mathbb^n, and ''Y'' is the feasible set of criterion vectors in \mathbb^m, such that Y = \. We assume that the preferred directions of criteria values are known. A point y^ \in \mathbb^m is preferred to (strictly dominates) another point y^ \in \mathbb^m, written as y^ \succ y^. The Pareto frontier is thus written as: : P(Y) = \. Marginal rate of substitution A significant aspect of the Pareto frontie ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IQM Quantum Computers
IQM may refer to: * Interquartile mean, a statistical measure * Qiemo Yudu Airport Qiemo Yudu Airport is an airport that serves Qiemo Town in Xinjiang Uyghur Autonomous Region, China. Located roughly northwest of the town, the airport has a terminal and a runway that measures . It replaced another airport serving the town ..., China (IATA code) ** Qiemo Airport (former) (former IATA code) * IQM Quantum Computers, a Finnish company involved in quantum computing {{Disambiguation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Forbes
''Forbes'' () is an American business magazine founded by B. C. Forbes in 1917. It has been owned by the Hong Kong–based investment group Integrated Whale Media Investments since 2014. Its chairman and editor-in-chief is Steve Forbes. The company is headquartered in Jersey City, New Jersey. Sherry Phillips is the current CEO of Forbes as of January 1, 2025. Published eight times per year, ''Forbes'' feature articles on finance, industry, investing, and marketing topics. It also reports on related subjects such as technology, communications, science, politics, and law. It has an international edition in Asia as well as editions produced under license in 27 countries and regions worldwide. The magazine is known for its lists and rankings, including its lists of the richest Americans (the Forbes 400, ''Forbes'' 400), of 30 notable people under the age of 30 (the Forbes 30 Under 30, ''Forbes'' 30 under 30), of America's wealthiest celebrities, of the world's top companies (the Fo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quantinuum
Quantinuum is a quantum computing company formed by the merger of Cambridge Quantum and Honeywell Quantum Solutions. The company's H-Series trapped-ion quantum computers set the highest quantum volume to date of 1,048,576 in April 2024. This architecture supports all-to-all qubit connectivity, allowing entangled states to be created between all qubits, and enables a high fidelity of quantum states. Quantinuum has developed middleware and software products that run on trapped-ion and other quantum computing platforms for cybersecurity, quantum chemistry, quantum machine learning, quantum Monte Carlo integration, and quantum artificial intelligence. The company also offers quantum-computing-hardened encryption keys designed to protect data assets and enhance cryptographic defenses. History Formed in 2021, Quantinuum is the combination of the quantum hardware team from Honeywell Quantum Solutions (HQS) and the quantum software team at Cambridge Quantum Computing (CQC). HQS was ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GitHub
GitHub () is a Proprietary software, proprietary developer platform that allows developers to create, store, manage, and share their code. It uses Git to provide distributed version control and GitHub itself provides access control, bug tracking system, bug tracking, software feature requests, task management, continuous integration, and wikis for every project. Headquartered in California, GitHub, Inc. has been a subsidiary of Microsoft since 2018. It is commonly used to host open source software development projects. GitHub reported having over 100 million developers and more than 420 million Repository (version control), repositories, including at least 28 million public repositories. It is the world's largest source code host Over five billion developer contributions were made to more than 500 million open source projects in 2024. About Founding The development of the GitHub platform began on October 19, 2005. The site was launched in April 2008 by Tom ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Toffoli Gate
In logic circuits, the Toffoli gate, also known as the CCNOT gate (“controlled-controlled-not”), invented by Tommaso Toffoli in 1980 is a CNOT gate with two control bits and one target bit. That is, the target bit (third bit) will be inverted if the first and second bits are both 1. It is a universal reversible logic gate, which means that any classical reversible circuit can be constructed from Toffoli gates. There is also a quantum-computing version where the bits are replaced by qubits. Description The truth table and permutation matrix are as follows (the permutation can be written (7,8) in cycle notation): Background An input-consuming logic gate ''L'' is reversible if it meets the following conditions: (1) ''L''(''x'') = ''y'' is a gate where for any output ''y'', there is a unique input ''x''; (2) The gate ''L'' is reversible if there is a gate ''L''´(''y'') = ''x'' which maps ''y'' to ''x'', for all ''y''. An example of a reversible logic gate is a NOT ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quantum (journal)
''Quantum'' is an online-only, open-access, peer-reviewed scientific journal for quantum science and related fields. The journal was established in 2017. ''Quantum'' is an arXiv overlay journal, meaning the journal's content is hosted on the arXiv. ''Quantum'' is listed in the Directory of Open Access Journals and the Emerging Sources Citation Index, and it is recognized by the European Physical Society as maintaining a high standard of peer review. See also * ''Discrete Analysis ''Discrete Analysis'' is a mathematics journal covering the applications of analysis to discrete structures. ''Discrete Analysis'' is an arXiv overlay journal, meaning the journal's content is hosted on the arXiv. History ''Discrete Analysis' ...'' References External links * Open access journals Physics journals Academic journals established in 2017 English-language journals Online-only journals {{physics-journal-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quantum Circuit
In quantum information theory, a quantum circuit is a model for quantum computation, similar to classical circuits, in which a computation is a sequence of quantum gates, measurements, initializations of qubits to known values, and possibly other actions. The minimum set of actions that a circuit needs to be able to perform on the qubits to enable quantum computation is known as DiVincenzo's criteria. Circuits are written such that the horizontal axis is time, starting at the left hand side and ending at the right. Horizontal lines are qubits, doubled lines represent classical bits. The items that are connected by these lines are operations performed on the qubits, such as measurements or gates. These lines define the sequence of events, and are usually not physical cables. The graphical depiction of quantum circuit elements is described using a variant of the Penrose graphical notation. Richard Feynman used an early version of the quantum circuit notation in 1986. Rever ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
