|
Atomic Mirror
In physics, an atomic mirror is a device which reflects neutral atoms in the similar way as a conventional mirror reflects visible light. Atomic mirrors can be made of electric fields or magnetic fields, electromagnetic waves or just silicon wafer; in the last case, atoms are reflected by the attracting tails of the van der Waals attraction (see quantum reflection). Such reflection is efficient when the normal component of the wavenumber of the atoms is small or comparable to the effective depth of the attraction potential (roughly, the distance at which the potential becomes comparable to the kinetic energy of the atom). To reduce the normal component, most atomic mirrors are blazed at the grazing incidence. At grazing incidence, the efficiency of the quantum reflection can be enhanced by a surface covered with ridges (ridged mirror). The set of narrow ridges reduces the van der Waals attraction of atoms to the surfaces and enhances the reflection. Each ridge blocks part o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Physics
Physics is the natural science that studies matter, its fundamental constituents, its motion and behavior through space and time, and the related entities of energy and force. "Physical science is that department of knowledge which relates to the order of nature, or, in other words, to the regular succession of events." Physics is one of the most fundamental scientific disciplines, with its main goal being to understand how the universe behaves. "Physics is one of the most fundamental of the sciences. Scientists of all disciplines use the ideas of physics, including chemists who study the structure of molecules, paleontologists who try to reconstruct how dinosaurs walked, and climatologists who study how human activities affect the atmosphere and oceans. Physics is also the foundation of all engineering and technology. No engineer could design a flat-screen TV, an interplanetary spacecraft, or even a better mousetrap without first understanding the basic laws of physic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ridged Mirror
In atomic physics, a ridged mirror (or ridged atomic mirror, or Fresnel diffraction mirror) is a kind of atomic mirror, designed for the specular reflection of neutral particles (atoms) coming at a grazing incidence angle. In order to reduce the mean attraction of particles to the surface and increase the reflectivity, this surface has narrow ridges. Reflectivity of ridged atomic mirrors Various estimates for the efficiency of quantum reflection of waves from ridged mirror were discussed in the literature. All the estimates explicitly use the de Broglie theory about wave properties of reflected atoms. Scaling of the van der Waals force The ridges enhance the quantum reflection from the surface, reducing the effective constant ~C~ of the van der Waals attraction of atoms to the surface. Such interpretation leads to the estimate of the reflectivity : \displaystyle r \approx r_0\!\left( \frac \ell L C,\!~K\sin(\theta)\right), where ~\ell~ is width of the ridges, ~L~ is distance ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Atomic Nanoscope
The atomic de Broglie microscope (also atomic nanoscope, neutral beam microscope, or scanning helium microscope when helium is used as the probing atom) is an imaging system which is expected to provide resolution at the nanometer scale. It is sometimes referred to as a "nanoscope." History The resolution of optical microscopes is limited to a few hundred nanometers by the wave properties of the light. The idea of imaging with atoms instead of light is widely discussed in the literature since the past century. Atom optics using neutral atoms instead of light could provide resolution as good as the electron microscope and be completely non-destructive, because short wavelengths on the order of a nanometer can be realized at low energy of the probing particles. "It follows that a helium microscope with nanometer resolution is possible. A helium atom microscope will be unique non-destructive tool for reflection or transmission microscopy." Focusing of neutral atoms Currently, the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ridged Mirror
In atomic physics, a ridged mirror (or ridged atomic mirror, or Fresnel diffraction mirror) is a kind of atomic mirror, designed for the specular reflection of neutral particles (atoms) coming at a grazing incidence angle. In order to reduce the mean attraction of particles to the surface and increase the reflectivity, this surface has narrow ridges. Reflectivity of ridged atomic mirrors Various estimates for the efficiency of quantum reflection of waves from ridged mirror were discussed in the literature. All the estimates explicitly use the de Broglie theory about wave properties of reflected atoms. Scaling of the van der Waals force The ridges enhance the quantum reflection from the surface, reducing the effective constant ~C~ of the van der Waals attraction of atoms to the surface. Such interpretation leads to the estimate of the reflectivity : \displaystyle r \approx r_0\!\left( \frac \ell L C,\!~K\sin(\theta)\right), where ~\ell~ is width of the ridges, ~L~ is distance ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quantum Reflection
Quantum reflection is a uniquely quantum phenomenon in which a compact object, such as a neutron or a small molecule, reflects smoothly and in a wavelike fashion from a much larger surface, such as a pool of mercury. In contrast, a classically behaving neutron or molecule will strike the same surface much like a thrown ball, hitting only at one atomic-scale location where it is either absorbed or scattered. Quantum reflection provides a powerful experimental demonstration of particle-wave duality, since it is the extended quantum wave packet of the particle, rather than the particle itself, that reflects from the larger surface. Definition Quantum reflection became an important branch of physics in the 21st century. In a workshop about quantum reflection,Quantum Reflection, workshop; October 22–24, 2007, Cambridge, Massachusetts, USA; http://cfa-www.harvard.edu/itamp/QuantumReflection.html the following definition of quantum reflection was suggested: Quantum reflection is a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Interferometry
Interferometry is a technique which uses the ''interference'' of superimposed waves to extract information. Interferometry typically uses electromagnetic waves and is an important investigative technique in the fields of astronomy, fiber optics, engineering metrology, optical metrology, oceanography, seismology, spectroscopy (and its applications to chemistry), quantum mechanics, nuclear and particle physics, plasma physics, remote sensing, biomolecular interactions, surface profiling, microfluidics, mechanical stress/strain measurement, velocimetry, optometry, and making holograms. Interferometers are devices that extract information from interference. They are widely used in science and industry for the measurement of microscopic displacements, refractive index changes and surface irregularities. In the case with most interferometers, light from a single source is split into two beams that travel in different optical paths, which are then combined again to produce interfer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Specular Reflection
Specular reflection, or regular reflection, is the mirror-like reflection of waves, such as light, from a surface. The law of reflection states that a reflected ray of light emerges from the reflecting surface at the same angle to the surface normal as the incident ray, but on the opposing side of the surface normal in the plane formed by the incident and reflected rays. This behavior was first described by Hero of Alexandria ( AD c. 10–70). Specular reflection may be contrasted with diffuse reflection, in which light is scattered away from the surface in a range of directions. Law of reflection When light encounters a boundary of a material, it is affected by the optical and electronic response functions of the material to electromagnetic waves. Optical processes, which comprise reflection and refraction, are expressed by the difference of the refractive index on both sides of the boundary, whereas reflectance and absorption are the real and imaginary parts of the re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zeno Effect
The quantum Zeno effect (also known as the Turing paradox) is a feature of quantum-mechanical systems allowing a particle's time evolution to be slowed down by measuring it frequently enough with respect to some chosen measurement setting. Sometimes this effect is interpreted as "a system cannot change while you are watching it". One can "freeze" the evolution of the system by measuring it frequently enough in its known initial state. The meaning of the term has since expanded, leading to a more technical definition, in which time evolution can be suppressed not only by measurement: the quantum Zeno effect is the suppression of unitary time evolution in quantum systems provided by a variety of sources: measurement, interactions with the environment, stochastic fields, among other factors. As an outgrowth of study of the quantum Zeno effect, it has become clear that applying a series of sufficiently strong and fast pulses with appropriate symmetry can also ''decouple'' a system ... [...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 m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Van Der Waals Force
In molecular physics, the van der Waals force is a distance-dependent interaction between atoms or molecules. Unlike ionic or covalent bonds, these attractions do not result from a chemical electronic bond; they are comparatively weak and therefore more susceptible to disturbance. The van der Waals force quickly vanishes at longer distances between interacting molecules. Named after Dutch physicist Johannes Diderik van der Waals, the van der Waals force plays a fundamental role in fields as diverse as supramolecular chemistry, structural biology, polymer science, nanotechnology, surface science, and condensed matter physics. It also underlies many properties of organic compounds and molecular solids, including their solubility in polar and non-polar media. If no other force is present, the distance between atoms at which the force becomes repulsive rather than attractive as the atoms approach one another is called the van der Waals contact distance; this phenomenon resul ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Optical Review
''Optical Review'' is a bimonthly peer-reviewed scientific journal that was established in 1994 and is published by Springer Science+Business Media in partnership with the Optical Society of Japan. The editor-in-chief is Masahiro Yamaguchi. The journal publishes research and review papers in all subdisciplines of optical science and optical engineering. Subdisciplines include general and physical optics, spectroscopy, quantum optics, optical computing, photonics, optoelectronics, lasers, nonlinear optics, environmental optics, adaptive optics, and space optics. Optics regarding the visible spectrum, infrared, and short wavelength optics are also included. Coverage encompasses required materials as well as suitable manufacturing tools, technologies, and methodologies. Abstracting and indexing The journal is abstracted and/or indexed in: According to the ''Journal Citation Reports'', the journal has a 2020 impact factor of 0.890. See also * ''Applied Physics Express'' * ''Japa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Journal Of The Physical Society Of Japan
''Journal of the Physical Society of Japan'' (''JPSJ'') is a monthly, peer reviewed, scientific journal published by the Physical Society of Japan (JPS). It was first published in July 1946 (volume 1). The editor-in-chief was A. Kawabata until August 2010. The impact factor for ''JPSJ'' in 2017 is 1.485, according to Journal Citation Reports. Volume 1 consists of a single issue designated, on the cover, from July to December 1946. And between 1967-1980 this journal published at a rate of two volumes per year. The other (Japanese) title for this journal is ''Nihon Butsuri Gakkai ōji hōkoku''. Volumes for 1967 to the present day are accompanied by an annual supplement. Research paper formats include full papers, letters, short notes, comments, addenda, errata, invited papers and special topics. Organizational structure The organizational structure of the journal is described as follows: The ''Full Papers'', ''Letters'' and ''Short Notes'' sections of the journal comprise the p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
