Quantum Computing

A quantum computer is a computer that exploits quantum mechanical phenomena. On small scales, physical matter exhibits properties of both particles and waves, and quantum computing leverages this behavior using specialized hardware. Classical physics cannot explain the operation of these quantum devices, and a scalable quantum computer could perform some calculations exponentially faster than any modern "classical" computer. In particular, a large-scale quantum computer could break widely used encryption schemes and aid physicists in performing 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 one of two states (a binary), a qubit can exist in a superposition of its two "basis" states, which loosely means that it is in both states simultaneously. When measuring a qubit, the result is a probabilistic output of a classical bit. If a quantum computer manipulates the qubit in a particular way, wave interference effects can amplify the desired measurement results. The design of quantum algorithms involves creating procedures that allow a quantum computer to perform calculations efficiently and quickly. Physically engineering high-quality qubits has proven challenging. If a physical qubit is not sufficiently isolated from its environment, it suffers from quantum decoherence, introducing noise into calculations. National governments have invested heavily in experimental research that aims to develop scalable 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). In principle, a classical computer can solve the same computational problems as a quantum computer, given enough time. Quantum advantage comes in the form of time complexity rather than computability, and quantum complexity theory shows that some quantum algorithms are exponentially more efficient than the best known classical algorithms. A large-scale quantum computer could in theory solve computational problems unsolvable by a classical computer in any reasonable amount of time. While claims of such quantum supremacy have drawn significant attention to the discipline, near-term practical use cases remain limited.

Article Title : Quantum computing
Article Snippet :waves, and quantum computing leverages this behavior using specialized hardware. Classical physics cannot explain the operation of these quantum devices
Article Title : Superconducting quantum computing
Article Snippet :Superconducting quantum computing is a branch of solid state quantum computing that implements superconducting electronic circuits using superconducting
Article Title : Timeline of quantum computing and communication
Article Snippet :This is a timeline of quantum computing. Stephen Wiesner invents conjugate coding (published in ACM SIGACT News 15(1): 78–88). James Park articulates
Article Title : Trapped-ion quantum computer
Article Snippet :quantum computing began to take off worldwide.[citation needed] In 2021, researchers from the University of Innsbruck presented a quantum computing demonstrator
Article Title : Quantum supremacy
Article Snippet :In quantum computing, quantum supremacy or quantum advantage is the goal of demonstrating that a programmable quantum computer can solve a problem that
Article Title : Quantum logic gate
Article Snippet :In quantum computing and specifically the quantum circuit model of computation, a quantum logic gate (or simply quantum gate) is a basic quantum circuit
Article Title : Quantum algorithm
Article Snippet :In quantum computing, a quantum algorithm is an algorithm that runs on a realistic model of quantum computation, the most commonly used model being the
Article Title : Glossary of quantum computing
Article Snippet :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 : Neuromorphic computing
Article Snippet :Neuromorphic computing is an approach to computing that is inspired by the structure and function of the human brain. A neuromorphic computer/chip is
Article Title : Adiabatic quantum computation
Article Snippet :Adiabatic quantum computation (AQC) is a form of quantum computing which relies on the adiabatic theorem to perform calculations and is closely related

waves, and quantum computing leverages this behavior using specialized hardware. Classical physics cannot explain the operation of these quantum devices

[source: wikipedia]