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Quantum Clock Model
The quantum clock model is a quantum lattice model. It is a generalisation of the transverse-field Ising model The transverse field Ising model is a quantum version of the classical Ising model. It features a lattice with nearest neighbour interactions determined by the alignment or anti-alignment of spin projections along the z axis, as well as an externa ... . It is defined on a lattice with N states on each site. The Hamiltonian of this model is :H = -J \left( \sum_ (Z^\dagger_i Z_j + Z_i Z^\dagger_j ) + g \sum_j (X_j + X^\dagger_j) \right) Here, the subscripts refer to lattice sites, and the sum \sum_ is done over pairs of nearest neighbour sites i and j. The clock matrices X_j and Z_j are N \times N generalisations of the Pauli matrices satisfying : Z_j X_k = e^ X_k Z_j and X_j^N = Z_j^N = 1 where \delta_ is 1 if j and k are the same site and zero otherwise. J is a prefactor with dimensions of energy, and g is another coupling coefficient that determines the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transverse-field Ising Model
The transverse field Ising model is a quantum version of the classical Ising model. It features a lattice with nearest neighbour interactions determined by the alignment or anti-alignment of spin projections along the z axis, as well as an external magnetic field perpendicular to the z axis (without loss of generality, along the x axis) which creates an energetic bias for one x-axis spin direction over the other. An important feature of this setup is that, in a quantum sense, the spin projection along the x axis and the spin projection along the z axis are not commuting observable quantities. That is, they cannot both be observed simultaneously. This means classical statistical mechanics cannot describe this model, and a quantum treatment is needed. Specifically, the model has the following quantum Hamiltonian: :H = -J\left(\sum_ Z_i Z_ + g \sum_j X_j \right) Here, the subscripts refer to lattice sites, and the sum \sum_ is done over pairs of nearest neighbour sites i and j. X_ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hamiltonian (quantum Mechanics)
Hamiltonian may refer to: * Hamiltonian mechanics, a function that represents the total energy of a system * Hamiltonian (quantum mechanics), an operator corresponding to the total energy of that system ** Dyall Hamiltonian, a modified Hamiltonian with two-electron nature ** Molecular Hamiltonian, the Hamiltonian operator representing the energy of the electrons and nuclei in a molecule * Hamiltonian (control theory), a function used to solve a problem of optimal control for a dynamical system * Hamiltonian path, a path in a graph that visits each vertex exactly once * Hamiltonian group, a non-abelian group the subgroups of which are all normal * Hamiltonian economic program, the economic policies advocated by Alexander Hamilton, the first United States Secretary of the Treasury See also * Alexander Hamilton (1755 or 1757–1804), American statesman and one of the Founding Fathers of the US * Hamilton (other) * List of things named after William Rowan Hamilton {{ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quantum Three-state Potts Model
The three-state Potts CFT, also known as the \mathbb_3 parafermion CFT, is a conformal field theory in two dimensions. It is a minimal model with central charge c=4/5 . It is considered to be the simplest minimal model with a non-diagonal partition function in Virasoro characters, as well as the simplest non-trivial CFT with the W-algebra as a symmetry. Properties The critical three-state Potts model has a central charge of c = 4/5 , and thus belongs to the discrete family of unitary minimal models with central charge less than one. These conformal field theories are fully classified and for the most part well-understood. The modular partition function of the critical three-state Potts model is given by :: Z = , \chi_ + \chi_, ^2 + , \chi_ + \chi_, ^2 + 2, \chi_, ^2+2, \chi_, ^2 Here \chi_ (q) \equiv \textrm_ (q^) refers to the Virasoro character, found by taking the trace over the Verma module generated from the Virasoro primary operator labeled by integers r, s . Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mathematical Modeling
A mathematical model is a description of a system using mathematical concepts and language. The process of developing a mathematical model is termed mathematical modeling. Mathematical models are used in the natural sciences (such as physics, biology, earth science, chemistry) and engineering disciplines (such as computer science, electrical engineering), as well as in non-physical systems such as the social sciences (such as economics, psychology, sociology, political science). The use of mathematical models to solve problems in business or military operations is a large part of the field of operations research. Mathematical models are also used in music, linguistics, and philosophy (for example, intensively in analytic philosophy). A model may help to explain a system and to study the effects of different components, and to make predictions about behavior. Elements of a mathematical model Mathematical models can take many forms, including dynamical systems, statistica ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
