|
Diffraction In Time
Diffraction in time is a phenomenon associated with the quantum dynamics of suddenly released matter waves initially confined in a region of space. It was introduced in 1952 by Marcos Moshinsky with the ''shutter problem''. A matter-wave beam stopped by an absorbing shutter exhibits an oscillatory density profile during its propagation after removal of the shutter. Whenever this propagation is accurately described by the time-dependent Schrödinger equation, the transient wave functions resemble the solutions that appear for the intensity of light subject to Fresnel diffraction by a straight edge. For this reason, the transient phenomenon was dubbed diffraction in time and has since then been recognised as ubiquitous in quantum dynamics. The experimental confirmation of this phenomenon was only achieved about half a century later in the group of ultracold atoms directed by Jean Dalibard Jean Dalibard (born 8 December 1958) is a French physicist, Professor at the École Polyt ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Matter Waves
Matter waves are a central part of the theory of quantum mechanics, being an example of wave–particle duality. All matter exhibits wave-like behavior. For example, a beam of electrons can be diffracted just like a beam of light or a water wave. In most cases, however, the wavelength is too small to have a practical impact on day-to-day activities. The concept that matter behaves like a wave was proposed by French physicist Louis de Broglie () in 1924. It is also referred to as the ''de Broglie hypothesis''. Matter waves are referred to as ''de Broglie waves''. The ''de Broglie wavelength'' is the wavelength, , associated with a massive particle (i.e., a particle with mass, as opposed to a massless particle) and is related to its momentum, , through the Planck constant, : : \lambda = \frac=\frac. Wave-like behavior of matter was first experimentally demonstrated by George Paget Thomson's thin metal diffraction experiment, and independently in the Davisson–Germer experime ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Marcos Moshinsky
Marcos Moshinsky Borodiansky (russian: Маркос Мошинский Бородянский; uk, Маркос Мошинскі; 1921–2009) was a Mexican physicist of Ukrainian- Jewish origin whose work in the field of elementary particles won him the Prince of Asturias Prize for Scientific and Technical Investigation in 1988 and the UNESCO Science Prize in 1997. Early life He was born in 1921 into a Jewish family in Kyiv, Ukrainian SSR. At the age of three, he emigrated as a refugee to Mexico, where he became a naturalized citizen in 1942. He received a bachelor's degree in physics from the National Autonomous University of Mexico (UNAM) and a doctorate in the same discipline at Princeton University under Nobel Laureate Eugene Paul Wigner. Career In the 1950s he researched nuclear reactions and the structure of the atomic nucleus, introducing the concept of the ''transformation bracket for eigenstates of the quantum harmonic oscillator'', which, together with the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Schrödinger Equation
The Schrödinger equation is a linear partial differential equation that governs the wave function of a quantum-mechanical system. It is a key result in quantum mechanics, and its discovery was a significant landmark in the development of the subject. The equation is named after Erwin Schrödinger, who postulated the equation in 1925, and published it in 1926, forming the basis for the work that resulted in his Nobel Prize in Physics in 1933. Conceptually, the Schrödinger equation is the quantum counterpart of Newton's second law in classical mechanics. Given a set of known initial conditions, Newton's second law makes a mathematical prediction as to what path a given physical system will take over time. The Schrödinger equation gives the evolution over time of a wave function, the quantum-mechanical characterization of an isolated physical system. The equation can be derived from the fact that the time-evolution operator must be unitary, and must therefore be generated ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fresnel Diffraction
In optics, the Fresnel diffraction equation for near-field diffraction is an approximation of the Kirchhoff–Fresnel diffraction that can be applied to the propagation of waves in the near field. It is used to calculate the diffraction pattern created by waves passing through an aperture or around an object, when viewed from relatively close to the object. In contrast the diffraction pattern in the far field region is given by the Fraunhofer diffraction equation. The near field can be specified by the Fresnel number, , of the optical arrangement. When F \gg 1 the diffracted wave is considered to be in the near field. However, the validity of the Fresnel diffraction integral is deduced by the approximations derived below. Specifically, the phase terms of third order and higher must be negligible, a condition that may be written as \frac \ll 1, where \theta is the maximal angle described by \theta \approx a/L, and the same as in the definition of the Fresnel number. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jean Dalibard
Jean Dalibard (born 8 December 1958) is a French physicist, Professor at the École Polytechnique, member of the French Academy of Sciences and a researcher at the École Normale Supérieure. In 2009, Dalibard received the Blaise Pascal medal of the European Academy of Sciences for "his outstanding and influential works in atomic physics and quantum optics". In 2012, he received the Max Born Award and Davisson–Germer Prize. He was elected an international member of the American Philosophical Society in 2018. In 2020, he was honoured to be an international member of the National Academy of Sciences. See also * Quantum jump method References External links * Lecture A lecture (from Latin ''lēctūra'' “reading” ) is an oral presentation intended to present information or teach people about a particular subject, for example by a university or college teacher. Lectures are used to convey critical infor ...s ''Mécanique quantique'' [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
.png "Click for more on -> Schrödinger Equation")
