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Principles Of Quantum Mechanics
Principles of Quantum Mechanics is a textbook by Ramamurti Shankar. The book has been through two editions. It is used in many college courses around the world. Contents # Mathematical Introduction # Review of Classical Mechanics # All Is Not Well with Classical Mechanics # The Postulates – a General Discussion # Simple Problems in One Dimension # The Classical Limit # The Harmonic Oscillator # The Path Integral Formulation of Quantum Theory # The Heisenberg Uncertainty Relations # Systems with N Degrees of Freedom # Symmetries and Their Consequences # Rotational Invariance and Angular Momentum # The Hydrogen Atom # Spin # Addition of Angular Momenta # Variational and WKB Methods # Time-Independent Perturbation Theory # Time-Dependent Perturbation Theory # Scattering Theory # The Dirac Equation In particle physics, the Dirac equation is a relativistic wave equation derived by British physicist Paul Dirac in 1928. In its free form, or including electromagnetic interac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ramamurti Shankar
Ramamurti Shankar (born April 28, 1947) is the Josiah Willard Gibbs professor of Physics at Yale University, in New Haven, Connecticut. Education He received his B. Tech in electrical engineering from the Indian Institute of Technology in Madras and his Ph.D. in theoretical particle physics from the University of California, Berkeley (1974). Career His research is in theoretical condensed matter physics, although he is also known for his earlier work in theoretical particle physics. In 2009, Shankar was awarded the Julius Edgar Lilienfeld Prize from the American Physical Society The American Physical Society (APS) is a not-for-profit membership organization of professionals in physics and related disciplines, comprising nearly fifty divisions, sections, and other units. Its mission is the advancement and diffusion of k ... for "innovative applications of field theoretic techniques to quantum condensed matter systems". After three years at the Harvard Society of Fell ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spin (physics)
Spin is a conserved quantity carried by elementary particles, and thus by composite particles ( hadrons) and atomic nuclei. Spin is one of two types of angular momentum in quantum mechanics, the other being ''orbital angular momentum''. The orbital angular momentum operator is the quantum-mechanical counterpart to the classical angular momentum of orbital revolution and appears when there is periodic structure to its wavefunction as the angle varies. For photons, spin is the quantum-mechanical counterpart of the polarization of light; for electrons, the spin has no classical counterpart. The existence of electron spin angular momentum is inferred from experiments, such as the Stern–Gerlach experiment, in which silver atoms were observed to possess two possible discrete angular momenta despite having no orbital angular momentum. The existence of the electron spin can also be inferred theoretically from the spin–statistics theorem and from the Pauli exclusion principle— ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Textbooks On Classical Mechanics And Quantum Mechanics
This is a list of notable textbooks on classical mechanics and quantum mechanics arranged according to level and surnames of the authors in alphabetical order. Undergraduate Classical mechanics * * * * * * * * Quantum mechanics * Three volumes. * * * * * * * * * * Advanced undergraduate and graduate Classical mechanics * * * * * * * * * Quantum mechanics * * *Landau, L. D, and Lifshitz, E. M. '' Course of Theoretical Physics Volume 3 - Quantum Mechanics: Non-Relativistic Theory''. Edited by Pitaevskiĭ L. P. Translated by J. B Sykes and J. S Bell, Third edition, revised and enlarged ed., Pergamon Press, 1977. . * * * * * See also * List of textbooks in thermodynamics and statistical mechanics * List of textbooks in electromagnetism * List of books on general relativity Further reading * * * External links A Physics Book List John Baez. Department of Mathematics, University of California, Riverside. 1993-1997. {{DEFAULTSORT:Classical mechanics and qua ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Modern Quantum Mechanics
''Modern Quantum Mechanics'', often called ''Sakurai'' or ''Sakurai and Napolitano'', is a standard graduate-level quantum mechanics textbook written originally by J. J. Sakurai and edited by San Fu Tuan in 1985, with later editions coauthored by Jim Napolitano. Sakurai died in 1982 before he could finish the textbook and both the first edition of the book, published in 1985 by Benjamin Cummings, and the revised edition of 1994, published by Addison-Wesley, were edited and completed by Tuan posthumously. The book was updated by Napolitano and released two later editions. The second edition was initially published by Addison-Wesley in 2010 and rereleased as an eBook by Cambridge University Press, who released a third edition in 2020. Table of Contents (3rd edition) * Prefaces * Chapter 1: Fundamental Concepts * Chapter 2: Quantum Dynamics * Chapter 3: Theory of Angular Momentum * Chapter 4: Symmetry in Quantum Mechanics * Chapter 5: Approximation Methods * Chapter 6: Scatterin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
American Scientist
__NOTOC__ ''American Scientist'' (informally abbreviated ''AmSci'') is an American bimonthly science and technology magazine published since 1913 by Sigma Xi, The Scientific Research Society. In the beginning of 2000s the headquarters was in New Haven, CT. Each issue includes feature articles written by prominent scientists and engineers who review research in fields from molecular biology to computer engineering. Each issue also includes the work of cartoonists, including those of Sidney Harris, Benita Epstein, and Mark Heath Sir Mark Evelyn Heath (27 May 1927 – 28 September 2005) was a British diplomat who served as British Envoy Extraordinary and Minister Plenipotentiary to the Holy See from 1980 to 1982 and the first Ambassador to the Holy See from 1982 to 1 .... Also included is the ''Scientists' Nightstand'' that reviews a vast range of science-related books and novels. ''American Scientist Online'' () was launched in May 2003. References External links * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dirac Equation
In particle physics, the Dirac equation is a relativistic wave equation derived by British physicist Paul Dirac in 1928. In its free form, or including electromagnetic interactions, it describes all spin- massive particles, called "Dirac particles", such as electrons and quarks for which parity is a symmetry. It is consistent with both the principles of quantum mechanics and the theory of special relativity, and was the first theory to account fully for special relativity in the context of quantum mechanics. It was validated by accounting for the fine structure of the hydrogen spectrum in a completely rigorous way. The equation also implied the existence of a new form of matter, ''antimatter'', previously unsuspected and unobserved and which was experimentally confirmed several years later. It also provided a ''theoretical'' justification for the introduction of several component wave functions in Pauli's phenomenological theory of spin. The wave functions in the Dirac t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Perturbation Theory (quantum Mechanics)
In quantum mechanics, perturbation theory is a set of approximation schemes directly related to mathematical perturbation for describing a complicated quantum system in terms of a simpler one. The idea is to start with a simple system for which a mathematical solution is known, and add an additional "perturbing" Hamiltonian representing a weak disturbance to the system. If the disturbance is not too large, the various physical quantities associated with the perturbed system (e.g. its energy levels and eigenstates) can be expressed as "corrections" to those of the simple system. These corrections, being small compared to the size of the quantities themselves, can be calculated using approximate methods such as asymptotic series. The complicated system can therefore be studied based on knowledge of the simpler one. In effect, it is describing a complicated unsolved system using a simple, solvable system. Approximate Hamiltonians Perturbation theory is an important tool fo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
WKB Approximation
In mathematical physics, the WKB approximation or WKB method is a method for finding approximate solutions to linear differential equations with spatially varying coefficients. It is typically used for a semiclassical calculation in quantum mechanics in which the wavefunction is recast as an exponential function, semiclassically expanded, and then either the amplitude or the phase is taken to be changing slowly. The name is an initialism for Wentzel–Kramers–Brillouin. It is also known as the LG or Liouville–Green method. Other often-used letter combinations include JWKB and WKBJ, where the "J" stands for Jeffreys. Brief history This method is named after physicists Gregor Wentzel, Hendrik Anthony Kramers, and Léon Brillouin, who all developed it in 1926. In 1923, mathematician Harold Jeffreys had developed a general method of approximating solutions to linear, second-order differential equations, a class that includes the Schrödinger equation. The Schrödinger equat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Variational Method (quantum Mechanics)
In quantum mechanics, the variational method is one way of finding approximations to the lowest energy eigenstate or ground state, and some excited states. This allows calculating approximate wavefunctions such as molecular orbitals. The basis for this method is the variational principle. The method consists of choosing a "trial wavefunction" depending on one or more parameters, and finding the values of these parameters for which the expectation value of the energy is the lowest possible. The wavefunction obtained by fixing the parameters to such values is then an approximation to the ground state wavefunction, and the expectation value of the energy in that state is an upper bound to the ground state energy. The Hartree–Fock method, Density matrix renormalization group, and Ritz method apply the variational method. Description Suppose we are given a Hilbert space and a Hermitian operator over it called the Hamiltonian H . Ignoring complications about continuous spectra, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrogen Atom
A hydrogen atom is an atom of the chemical element hydrogen. The electrically neutral atom contains a single positively charged proton and a single negatively charged electron bound to the nucleus by the Coulomb force. Atomic hydrogen constitutes about 75% of the baryonic mass of the universe. In everyday life on Earth, isolated hydrogen atoms (called "atomic hydrogen") are extremely rare. Instead, a hydrogen atom tends to combine with other atoms in compounds, or with another hydrogen atom to form ordinary ( diatomic) hydrogen gas, H2. "Atomic hydrogen" and "hydrogen atom" in ordinary English use have overlapping, yet distinct, meanings. For example, a water molecule contains two hydrogen atoms, but does not contain atomic hydrogen (which would refer to isolated hydrogen atoms). Atomic spectroscopy shows that there is a discrete infinite set of states in which a hydrogen (or any) atom can exist, contrary to the predictions of classical physics. Attempts to develop a th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paul Dirac
Paul Adrien Maurice Dirac (; 8 August 1902 – 20 October 1984) was an English theoretical physicist who is regarded as one of the most significant physicists of the 20th century. He was the Lucasian Professor of Mathematics at the University of Cambridge, a professor of physics at Florida State University and the University of Miami, and a 1933 Nobel Prize recipient. Dirac made fundamental contributions to the early development of both quantum mechanics and quantum electrodynamics. Among other discoveries, he formulated the Dirac equation which describes the behaviour of fermions and predicted the existence of antimatter. Dirac shared the 1933 Nobel Prize in Physics with Erwin Schrödinger "for the discovery of new productive forms of atomic theory". He also made significant contributions to the reconciliation of general relativity with quantum mechanics. Dirac was regarded by his friends and colleagues as unusual in character. In a 1926 letter to Paul Ehrenfest, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Angular Momentum
In physics, angular momentum (rarely, moment of momentum or rotational momentum) is the rotational analog of linear momentum. It is an important physical quantity because it is a conserved quantity—the total angular momentum of a closed system remains constant. Angular momentum has both a direction and a magnitude, and both are conserved. Bicycles and motorcycles, frisbees, rifled bullets, and gyroscopes owe their useful properties to conservation of angular momentum. Conservation of angular momentum is also why hurricanes form spirals and neutron stars have high rotational rates. In general, conservation limits the possible motion of a system, but it does not uniquely determine it. The three-dimensional angular momentum for a point particle is classically represented as a pseudovector , the cross product of the particle's position vector (relative to some origin) and its momentum vector; the latter is in Newtonian mechanics. Unlike linear momentum, angular mome ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
