Quantum Computing

A quantum computer is a computer that represents and processes information using quantum states. Quantum computations exploit phenomena such as superposition, interference, and entanglement. Quantum computers have the potential to complete some calculations exponentially faster than classical computers. For example, a large-scale quantum computer could break widely used encryption schemes and aid physicists in performing physical simulations. However, current hardware implementations of quantum computation are largely experimental and suitable for only certain specialized tasks. The basic unit of information in quantum computing, the qubit (quantum bit), serves a similar function as the bit in ordinary or "classical" computing. Unlike a classical bit, which can be in one of two states (a binary), a qubit can exist in a linear combination of states known as a quantum superposition. The result of measuring a qubit is one of the two states, given by a probabilistic rule. If a quantum computer manipulates the qubit in a particular way, wave interference effects amplify the probability of the desired measurement result. Quantum algorithm design involves creating procedures that allow a quantum computer to perform this amplification. Quantum computers are not yet practical for real-world applications. If a physical qubit is not sufficiently isolated from its environment, it suffers from quantum decoherence, introducing noise (error) into calculations. Governments have invested in research aimed at developing qubits with longer coherence times and lower error rates. Example implementations include superconductors (which isolate an electrical current by eliminating electrical resistance) and ion traps (which confine a single atomic particle using electromagnetic fields). Researchers have claimed that quantum devices can outperform classical computers on specific tasks, a metric referred to as quantum advantage or quantum supremacy. Such tasks are not necessarily useful for real-world applications. As a result, as of 2026 demonstrations are best understood as scientific milestones rather than evidence for near-term deployment. Global government investment in quantum computing reached $10 billion by April 2025.

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Article title : Quantum computing
"List of quantum computing journals List of quantum computing books List of quantum software Magic state distillation – Quantum computing algorithm Metacomputing –..."
Article title : Superconducting quantum computing
"quantum computing is a branch of quantum computing and solid-state physics that implements superconducting electronic circuits as qubits in a quantum..."
Article title : Timeline of quantum computing and communication
"timeline of quantum computing and communication. Erwin Schrödinger publishes a theorem setting the basis for quantum steering and the limits of quantum state..."
Article title : Topological quantum computer
"simulation results. One of the prominent examples in topological quantum computing is with a system of Fibonacci anyons. A Fibonacci anyon has been described..."
Article title : Trapped-ion quantum computer
"quantum computing began to accelerate worldwide.[citation needed] In 2021, researchers from the University of Innsbruck presented a quantum computing..."
Article title : Post-quantum cryptography
"quantum computing". phys.org. Heger, Monica (2009-01-01). "Cryptographers Take On Quantum Computers". IEEE Spectrum. "Q&A With Post-Quantum Computing..."
Article title : Glossary of quantum computing
"This glossary of quantum computing is a list of definitions of terms and concepts used in quantum computing, its sub-disciplines, and related fields. Bacon–Shor..."
Article title : Institute for Quantum Computing
"The Institute for Quantum Computing (IQC) is an affiliate scientific research institute of the University of Waterloo located in Waterloo, Ontario with..."
Article title : Silicon Quantum Computing
"Quantum Computing Pty Ltd (SQC) is a Sydney, Australia-based quantum computing company. The company develops quantum computers and analogue quantum devices..."
Article title : QuEra
"Performance Computing Center announced a $16 million expansion to its computing campus, planning to build a quantum computing complex. QuEra Computing was announced..."

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List of quantum computing journals List of quantum computing books List of quantum software Magic state distillation – Quantum computing algorithm Metacomputing –

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[source: wikipedia]