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Ramsey Interferometry
Ramsey interferometry, also known as the separated oscillating fields method, is a form of particle interferometry that uses the phenomenon of magnetic resonance to measure transition frequencies of particles. It was developed in 1949 by Norman Ramsey, who built upon the ideas of his mentor, Isidor Isaac Rabi, who initially developed a technique for measuring particle transition frequencies. Ramsey's method is used today in atomic clocks and in the SI definition of the second. Most precision atomic measurements, such as modern atom interferometers and quantum logic gates, have a Ramsey-type configuration.Deutsch, Ivan. ''Quantum Optics I, PHYS 566, at the University of New Mexico''. Problem Set 3 and Solutions. Fall 2013. A more modern method, known as Ramsey–Bordé interferometry uses a Ramsey configuration and was developed by French physicist Christian Bordé and is known as the Ramsey–Bordé interferometer. Bordé's main idea was to use atomic recoil to create a beam sp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nuclear Magnetic Resonance
Nuclear magnetic resonance (NMR) is a physical phenomenon in which nuclei in a strong constant magnetic field are disturbed by a weak oscillating magnetic field (in the near field) and respond by producing an electromagnetic signal with a frequency characteristic of the magnetic field at the nucleus. This process occurs near resonance, when the oscillation frequency matches the intrinsic frequency of the nuclei, which depends on the strength of the static magnetic field, the chemical environment, and the magnetic properties of the isotope involved; in practical applications with static magnetic fields up to ca. 20 tesla, the frequency is similar to VHF and UHF television broadcasts (60–1000 MHz). NMR results from specific magnetic properties of certain atomic nuclei. High-resolution nuclear magnetic resonance spectroscopy is widely used to determine the structure of organic molecules in solution and study molecular physics and crystals as well as non-crysta ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rabi Cycle
In physics, the Rabi cycle (or Rabi flop) is the cyclic behaviour of a two-level quantum system in the presence of an oscillatory driving field. A great variety of physical processes belonging to the areas of quantum computing, condensed matter, atomic and molecular physics, and nuclear and particle physics can be conveniently studied in terms of two-level quantum mechanical systems, and exhibit Rabi flopping when coupled to an optical driving field. The effect is important in quantum optics, magnetic resonance, and quantum computing, and is named after Isidor Isaac Rabi. A two-level system is one that has two possible energy levels. One level is a ground state with lower energy, and the other is an excited state with higher energy. If the energy levels are not degenerate (i.e. don't have equal energies), the system can absorb or emit a quantum of energy and transition from the ground state to the excited state or vice versa. When an atom (or some other two-level system) is illu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Serge Haroche
Serge Haroche (born 11 September 1944) is a French physicist who was awarded the 2012 Nobel Prize for Physics jointly with David J. Wineland for "ground-breaking experimental methods that enable measuring and manipulation of individual quantum systems", a study of the particle of light, the photon. This and his other works developed laser spectroscopy. Since 2001, Haroche is a professor at the Collège de France and holds the chair of quantum physics and in 2022 he had the Fermi Chair of Physics at University of Rome La Sapienza In 1971 he defended his doctoral thesis in physics at the University of Paris VI: his research had been conducted under the direction of Claude Cohen-Tannoudji. Early life and education Haroche was born in Casablanca, Morocco, to Albert Haroche (1920–1998), from a Moroccan Jewish family, and Valentine Haroche, born Roubleva (1921–1998), a teacher who was born in Odessa to a Jewish family of physicians who relocated to Morocco in the early 1920s. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Second
The second (symbol: s) is a unit of time derived from the division of the day first into 24 hours, then to 60 minutes, and finally to 60 seconds each (24 × 60 × 60 = 86400). The current and formal definition in the International System of Units (SI) is more precise: The second ..is defined by taking the fixed numerical value of the caesium frequency, Δ''ν''Cs, the unperturbed ground-state hyperfine transition frequency of the caesium 133 atom, to be when expressed in the unit Hz, which is equal to s−1. This current definition was adopted in 1967 when it became feasible to define the second based on fundamental properties of nature with caesium clocks. As the speed of Earth's rotation varies and is slowing ever so slightly, a leap second is added at irregular intervals to civil time to keep clocks in sync with Earth's rotation. The definition that is based on of a rotation of the earth is still used by the Universal Time 1 (UT1) system. Etymology "Minute" ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Frequency Domain
In mathematics, physics, electronics, control systems engineering, and statistics, the frequency domain refers to the analysis of mathematical functions or signals with respect to frequency (and possibly phase), rather than time, as in time series. While a time-domain graph shows how a signal changes over time, a frequency-domain graph shows how the signal is distributed within different frequency bands over a range of frequencies. A complex valued frequency-domain representation consists of both the magnitude and the phase of a set of sinusoids (or other basis waveforms) at the frequency components of the signal. Although it is common to refer to the magnitude portion (the real valued frequency-domain) as the frequency response of a signal, the phase portion is required to uniquely define the signal. A given function or signal can be converted between the time and frequency domains with a pair of mathematical operators called transforms. An example is the Fourier transfo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bloch Sphere
In quantum mechanics and computing, the Bloch sphere is a geometrical representation of the pure state space of a two-level quantum mechanical system ( qubit), named after the physicist Felix Bloch. Mathematically each quantum mechanical system is associated with a separable complex Hilbert space H. A pure state of a quantum system is represented by a non-zero vector \psi in H. As the vectors \psi and \lambda \psi (with \lambda \in \mathbb^*) represent the same state, the level of the quantum system corresponds to the dimension of the Hilbert space and pure states can be represented as equivalence classes, or, rays in a projective Hilbert space \mathbf(H_)=\mathbb\mathbf^. For a two-dimensional Hilbert space, the space of all such states is the complex projective line \mathbb\mathbf^1. This is the Bloch sphere, which can be mapped to the Riemann sphere. The Bloch sphere is a unit 2-sphere, with antipodal points corresponding to a pair of mutually orthogonal state vec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rotating-wave Approximation
The rotating-wave approximation is an approximation used in atom optics and magnetic resonance. In this approximation, terms in a Hamiltonian that oscillate rapidly are neglected. This is a valid approximation when the applied electromagnetic radiation is near resonance with an atomic transition, and the intensity is low. Explicitly, terms in the Hamiltonians that oscillate with frequencies \omega_L + \omega_0 are neglected, while terms that oscillate with frequencies \omega_L - \omega_0 are kept, where \omega_L is the light frequency, and \omega_0 is a transition frequency. The name of the approximation stems from the form of the Hamiltonian in the interaction picture, as shown below. By switching to this picture the evolution of an atom due to the corresponding atomic Hamiltonian is absorbed into the system ket, leaving only the evolution due to the interaction of the atom with the light field to consider. It is in this picture that the rapidly oscillating terms mentioned prev ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Larmor Precession
Sir Joseph Larmor (; 11 July 1857 – 19 May 1942) was an Irish mathematician and physicist who made breakthroughs in the understanding of electricity, dynamics, thermodynamics, and the electron theory of matter. His most influential work was ''Aether and Matter'', a theoretical physics book published in 1900. Biography He was born in Magheragall in County Antrim, the son of Hugh Larmor, a Belfast shopkeeper and his wife, Anna Wright. The family moved to Belfast circa 1860, and he was educated at the Royal Belfast Academical Institution, and then studied mathematics and experimental science at Queen's College, Belfast (BA 1874, MA 1875), where one of his teachers was John Purser. He subsequently studied at St John's College, Cambridge, where in 1880 he was Senior Wrangler ( J. J. Thomson was second wrangler that year) and Smith's Prizeman, getting his MA in 1883. After teaching physics for a few years at Queen's College, Galway, he accepted a lectureship in mathematics at ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Norman Ramsey Jr
Norman or Normans may refer to: Ethnic and cultural identity * The Normans, a people partly descended from Norse Vikings who settled in the territory of Normandy in France in the 9th and 10th centuries ** People or things connected with the Norman conquest of southern Italy in the 11th and 12th centuries ** Normanist theory (also known as Normanism) and anti-Normanism, historical disagreement regarding the origin of Russia, Ukraine, Belarus and their historic predecessor, Kievan Rus' ** Norman dynasty, a series of monarchs in England and Normandy ** Norman architecture, romanesque architecture in England and elsewhere ** Norman language, spoken in Normandy ** People or things connected with the French region of Normandy Arts and entertainment * ''Norman'' (2010 film), a 2010 drama film * ''Norman'' (2016 film), a 2016 drama film * ''Norman'' (TV series), a 1970 British sitcom starring Norman Wisdom * ''The Normans'' (TV series), a documentary * "Norman" (song), a 1962 song w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Beam Splitter
A beam splitter or beamsplitter is an optical instrument, optical device that splits a beam of light into a transmitted and a reflected beam. It is a crucial part of many optical experimental and measurement systems, such as Interferometry, interferometers, also finding widespread application in fibre optic telecommunications. Designs In its most common form, a cube, a beam splitter is made from two triangular glass prism (optics), prisms which are glued together at their base using polyester, epoxy, or urethane-based adhesives. (Before these synthetic resins, natural ones were used, e.g. Canada balsam.) The thickness of the resin layer is adjusted such that (for a certain wavelength) half of the light incident through one "port" (i.e., face of the cube) is reflection (physics), reflected and the other half is transmitted due to Total internal reflection#Frustrated_TIR, FTIR (frustrated total internal reflection). polarizer, Polarizing beam splitters, such as the Wollaston prism ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Christian Bordé
Christian Bordé (15 March 1943 - 30 August 2023) was a French physicist. He has been a member of the French Academy of Sciences since December 2008. Biography Emeritus research director at the CNRS, he is known for his work in the field of ultra-high resolution laser spectroscopy. He invented and developed saturation spectroscopy, which he used to study many new and fundamental effects in molecular physics. His name is attached to the design of a whole class of atomic interferometers based on the recoil effect, which make it possible to produce optical clocks, measure atomic masses and probe the properties of space-time. In particular, he demonstrated that these interferometers allowed very accurate measurement of the fields of inertia. The proximity of his work to the field of metrology has led it to preside on several occasions, on behalf of the French Academy of Sciences, over the meetings of the General Conference on Weights and Measures, the executive organ of the Metre Con ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
