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Quantum Dot Cellular Automaton
Quantum dot cellular automata (QDCA, sometimes referred to simply as quantum cellular automata, or QCA) are a proposed improvement on conventional computer design (CMOS), which have been devised in analogy to conventional models of cellular automata introduced by John von Neumann. Background Any device designed to represent data and perform computation, regardless of the physics principles it exploits and materials used to build it, must have two fundamental properties: distinguishability and conditional change of state, the latter implying the former. This means that such a device must have barriers that make it possible to distinguish between states, and that it must have the ability to control these barriers to perform conditional change of state. For example, in a digital electronic system, transistors play the role of such controllable energy barriers, making it extremely practical to perform computing with them. Cellular automata A cellular automaton (CA) is a discrete dy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quantum Cellular Automaton
A quantum cellular automaton (QCA) is an abstract model of quantum computation, devised in analogy to conventional models of cellular automata introduced by John von Neumann. The same name may also refer to quantum dot cellular automata, which are a proposed physical implementation of "classical" cellular automata by exploiting quantum mechanical phenomena. QCA have attracted a lot of attention as a result of its extremely small feature size (at the molecular or even atomic scale) and its ultra-low power consumption, making it one candidate for replacing CMOS technology. Usage of the term In the context of models of computation or of physical systems, ''quantum cellular automaton'' refers to the merger of elements of both (1) the study of cellular automata in conventional computer science and (2) the study of quantum information processing. In particular, the following are features of models of quantum cellular automata: * The computation is considered to come about by p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quantum Tunnelling
In physics, quantum tunnelling, barrier penetration, or simply tunnelling is a quantum mechanical phenomenon in which an object such as an electron or atom passes through a potential energy barrier that, according to classical mechanics, should not be passable due to the object not having sufficient energy to pass or surmount the barrier. Tunneling is a consequence of the wave nature of matter, where the quantum wave function describes the state of a particle or other physical system, and wave equations such as the Schrödinger equation describe their behavior. The probability of transmission of a wave packet through a barrier decreases exponentially with the barrier height, the barrier width, and the tunneling particle's mass, so tunneling is seen most prominently in low-mass particles such as electrons or protons tunneling through microscopically narrow barriers. Tunneling is readily detectable with barriers of thickness about 1–3 nm or smaller for electrons, and abou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
OR Gate
The OR gate is a digital logic gate that implements logical disjunction. The OR gate outputs "true" if any of its inputs is "true"; otherwise it outputs "false". The input and output states are normally represented by different voltage levels. Description Any OR gate can be constructed with two or more inputs. It outputs a 1 if any of these inputs are 1, or outputs a 0 only if all inputs are 0. The inputs and outputs are binary digits ("bits") which have two possible truth value, logical states. In addition to 1 and 0, these states may be called true and false, high and low, active and inactive, or other such pairs of symbols. Thus it performs a logical disjunction (∨) from mathematical logic. The gate can be represented with the plus sign (+) because it can be used for Disjunction introduction, logical addition. Equivalently, an OR gate finds the ''maximum'' between two binary digits, just as the AND gate finds the ''minimum''. Together with the AND gate and the NOT gate, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
AND Gate
The AND gate is a basic digital logic gate that implements the logical conjunction (∧) from mathematical logic AND gates behave according to their truth table. A HIGH output (1) results only if all the inputs to the AND gate are HIGH (1). If any of the inputs to the AND gate are not HIGH, a LOW (0) is outputted. The function can be extended to any number of inputs by multiple gates up in a chain. Symbols There are three symbols for AND gates: the American (ANSI or 'military') symbol and the IEC ('European' or 'rectangular') symbol, as well as the deprecated DIN symbol. Additional inputs can be added as needed. For more information see the Logic gate symbols article. It can also be denoted as symbol "^" or "&". The AND gate with inputs ''A'' and ''B'' and output ''C'' implements the logical expression C = A \cdot B. This expression also may be denoted as C=A \wedge B or C=A \And B. As of Unicode 16.0.0, the AND gate is also encoded in the Symbols for Legacy Computing Su ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CA05
CA most often refers to: * Canada, a country by ISO 3166-1 alpha-2 code * California, U.S. state by postal abbreviation CA or ca may also refer to: Businesses and organizations Companies * Air China (IATA airline code CA) * CA Technologies, a U.S. software company * Cayman Airways, a Cayman Islands airline * Channel America, a defunct U.S. television network * Coal & Allied, Australian mining company * Continental Airlines, a U.S. airline * Creative Assembly, a PC game developer * Crédit Agricole, a major French bank Government and political * Bureau of Consular Affairs, a division of the U.S. Department of State * Canadian Alliance, a former Canadian political party * Centre Alliance, Australian political party formerly known as Nick Xenophon Team * Citizens' Alliance, a political party in Trinidad and Tobago * Combined authority, a local government entity in the United Kingdom * Commission on Appointments, a body of the Congress of the Philippines * Conservatives Abroad, ov ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Logic Gates
A logic gate is a device that performs a Boolean function, a logical operation performed on one or more Binary number, binary inputs that produces a single binary output. Depending on the context, the term may refer to an ideal logic gate, one that has, for instance, zero rise time and unlimited fan-out, or it may refer to a non-ideal physical device (see ideal and real op-amps for comparison). The primary way of building logic gates uses diodes or transistors acting as electronic switches. Today, most logic gates are made from MOSFETs (metal–oxide–semiconductor field-effect transistors). ''From Integrated circuit'' They can also be constructed using vacuum tubes, electromagnetic relays with relay logic, fluidic logic, pneumatics#Pneumatic logic, pneumatic logic, optics, molecular logic gate, molecules, acoustics, or even Analytical Engine, mechanical or thermal elements. Logic gates can be cascaded in the same way that Boolean functions can be composed, allowing the constr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coulomb Barrier
The Coulomb barrier, named after Coulomb's law, which is in turn named after physicist Charles-Augustin de Coulomb, is the energy barrier due to electrostatic interaction that two nuclei need to overcome so they can get close enough to undergo a nuclear reaction. Potential energy barrier This energy barrier is given by the electric potential energy: :U_\text = where :''ε''0 is the permittivity of free space; :''q''1, ''q''2 are the charges of the interacting particles; :''r'' is the interaction radius. A positive value of ''U'' is due to a repulsive force, so interacting particles are at higher energy levels as they get closer. A negative potential energy indicates a bound state (due to an attractive force). The Coulomb barrier increases with the atomic numbers (i.e. the number of protons) of the colliding nuclei: :U_\text = where ''e'' is the elementary charge, and ''Zi'' the corresponding atomic numbers. To overcome this barrier, nuclei have to collide at high velocities, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Series And Parallel Circuits
Two-terminal components and electrical networks can be connected in series or parallel. The resulting electrical network will have two terminals, and itself can participate in a series or parallel topology. Whether a two-terminal "object" is an electrical component (e.g. a resistor) or an electrical network (e.g. resistors in series) is a matter of perspective. This article will use "component" to refer to a two-terminal "object" that participates in the series/parallel networks. Components connected in series are connected along a single "electrical path", and each component has the same electric current through it, equal to the current through the network. The voltage across the network is equal to the sum of the voltages across each component. Components connected in parallel are connected along multiple paths, and each component has the same voltage across it, equal to the voltage across the network. The current through the network is equal to the sum of the currents thr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CA04
CA most often refers to: * Canada, a country by ISO 3166-1 alpha-2 code * California, U.S. state by postal abbreviation CA or ca may also refer to: Businesses and organizations Companies * Air China (IATA airline code CA) * CA Technologies, a U.S. software company * Cayman Airways, a Cayman Islands airline * Channel America, a defunct U.S. television network * Coal & Allied, Australian mining company * Continental Airlines, a U.S. airline * Creative Assembly, a PC game developer * Crédit Agricole, a major French bank Government and political * Bureau of Consular Affairs, a division of the U.S. Department of State * Canadian Alliance, a former Canadian political party * Centre Alliance, Australian political party formerly known as Nick Xenophon Team * Citizens' Alliance, a political party in Trinidad and Tobago * Combined authority, a local government entity in the United Kingdom * Commission on Appointments, a body of the Congress of the Philippines * Conservatives Abroad, ove ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Boolean Algebra (logic)
In mathematics and mathematical logic, Boolean algebra is a branch of algebra. It differs from elementary algebra in two ways. First, the values of the variable (mathematics), variables are the truth values ''true'' and ''false'', usually denoted by 1 and 0, whereas in elementary algebra the values of the variables are numbers. Second, Boolean algebra uses logical operators such as Logical conjunction, conjunction (''and'') denoted as , disjunction (''or'') denoted as , and negation (''not'') denoted as . Elementary algebra, on the other hand, uses arithmetic operators such as addition, multiplication, subtraction, and division. Boolean algebra is therefore a formal way of describing logical operations in the same way that elementary algebra describes numerical operations. Boolean algebra was introduced by George Boole in his first book ''The Mathematical Analysis of Logic'' (1847), and set forth more fully in his ''An Investigation of the Laws of Thought'' (1854). According to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Photon Polarization
Photon polarization is the quantum mechanical description of the classical polarized sinusoidal plane electromagnetic wave. An individual photon can be described as having right or left circular polarization, or a superposition of the two. Equivalently, a photon can be described as having horizontal or vertical linear polarization, or a superposition of the two. The description of photon polarization contains many of the physical concepts and much of the mathematical machinery of more involved quantum descriptions, such as the quantum mechanics of an electron in a potential well. Polarization is an example of a qubit degree of freedom, which forms a fundamental basis for an understanding of more complicated quantum phenomena. Much of the mathematical machinery of quantum mechanics, such as state vectors, probability amplitudes, unitary operators, and Hermitian operators, emerge naturally from the classical Maxwell's equations in the description. The quantum polarizatio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Energy Level
A quantum mechanics, quantum mechanical system or particle that is bound state, bound—that is, confined spatially—can only take on certain discrete values of energy, called energy levels. This contrasts with classical mechanics, classical particles, which can have any amount of energy. The term is commonly used for the energy levels of the electrons in atoms, ions, or molecules, which are bound by the electric field of the atomic nucleus, nucleus, but can also refer to energy levels of nuclei or molecular vibration, vibrational or rotational energy levels in molecules. The energy spectrum of a system with such discrete energy levels is said to be Quantization (physics), quantized. In chemistry and atomic physics, an electron shell, or principal energy level, may be thought of as the orbit of one or more electrons around an atom's atomic nucleus, nucleus. The closest shell to the nucleus is called the "1 shell" (also called "K shell"), followed by the "2 shell" (or "L shell"), ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
