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Conductance Fluctuations
Universal conductance fluctuations (UCF) in mesoscopic physics is a phenomenon encountered in electrical transport experiments in mesoscopic species. The measured electrical conductance will vary from sample to sample, mainly due to inhomogeneous scattering sites. Fluctuations originate from coherence effects for electronic wavefunctions and thus the phase-coherence length \textstyle l_\phi needs be larger than the momentum relaxation length \textstyle l_m. UCF is more profound when electrical transport is in weak localization regime. \textstyle l_\phi [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mesoscopic Physics
Mesoscopic physics is a subdiscipline of condensed matter physics that deals with materials of an intermediate size. These materials range in size between the nanoscale for a quantity of atoms (such as a molecule) and of materials measuring micrometres. The lower limit can also be defined as being the size of individual atoms. At the micrometre level are bulk materials. Both mesoscopic and macroscopic objects contain many atoms. Whereas average properties derived from constituent materials describe macroscopic objects, as they usually obey the laws of classical mechanics, a mesoscopic object, by contrast, is affected by thermal fluctuations around the average, and its electronic behavior may require modeling at the level of quantum mechanics.Sci-Tech Dictionary. McGraw-Hill Dictionary of Scientific and Technical Terms. 2003. McGraw-Hill Companies, Inc A macroscopic electronic device, when scaled down to a meso-size, starts revealing quantum mechanical properties. For example, at ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electrical Conductance
The electrical resistance of an object is a measure of its opposition to the flow of electric current. Its reciprocal quantity is , measuring the ease with which an electric current passes. Electrical resistance shares some conceptual parallels with mechanical friction. The SI unit of electrical resistance is the ohm (), while electrical conductance is measured in siemens (S) (formerly called the 'mho' and then represented by ). The resistance of an object depends in large part on the material it is made of. Objects made of electrical insulators like rubber tend to have very high resistance and low conductance, while objects made of electrical conductors like metals tend to have very low resistance and high conductance. This relationship is quantified by resistivity or conductivity. The nature of a material is not the only factor in resistance and conductance, however; it also depends on the size and shape of an object because these properties are extensive rather than inten ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Weak Localization
Weak localization is a physical effect which occurs in disordered electronic systems at very low temperatures. The effect manifests itself as a ''positive'' correction to the resistivity of a metal or semiconductor. The name emphasizes the fact that weak localization is a precursor of Anderson localization, which occurs at strong disorder. General principle The effect is quantum-mechanical in nature and has the following origin: In a disordered electronic system, the electron motion is diffusive rather than ballistic. That is, an electron does not move along a straight line, but experiences a series of random scatterings off impurities which results in a random walk. The resistivity of the system is related to the probability of an electron to propagate between two given points in space. Classical physics assumes that the total probability is just the sum of the probabilities of the paths connecting the two points. However quantum mechanics tells us that to find the total probabilit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Speckle Pattern
Speckle, speckle pattern, or speckle noise is a granular noise texture degrading the quality as a consequence of interference among wavefronts in coherent imaging systems, such as radar, synthetic aperture radar (SAR), medical ultrasound and optical coherence tomography. Speckle is not external noise; rather, it is an inherent fluctuation in diffuse reflections, because the scatterers are not identical for each cell, and the coherent illumination wave is highly sensitive to small variations in phase changes. Although scientists have investigated this phenomenon since the time of Newton, speckles have come into prominence since the invention of the laser. Such reflections may occur on materials such as paper, white paint, rough surfaces, or in media with a large number of scattering particles in space, such as airborne dust or in cloudy liquids. They have been used in a variety of applications in microscopy, imaging, and optical manipulation. The vast majority of surfaces, synt ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Supriyo Datta
Supriyo Datta (born 1954) is an Indian born American researcher and author. A leading figure in the modeling and understanding of nano-scale electronic conduction, he has been called "one of the most original thinkers in the field of nanoscale electronics." As an author, his books are widely used as original research and design work in the field of nanotechnology and electronic devices. Early life and education Dr. Datta did his schooling from Hindi High School in Kolkata, India. He was first in the whole West Bengal Board of Secondary Education exam in 1970. Datta received his B.Tech with the President of India gold medal from the Indian Institute of Technology in Kharagpur, India in 1975. He then received both his MS and PhD from the University of Illinois at Urbana-Champaign in 1977 and 1979 respectively. In 1981, he joined Purdue University, where he is (since 1999) the Thomas Duncan Distinguished Professor in the School of Electrical Engineering. Career He started his ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mildred Dresselhaus
Mildred Dresselhaus''Mildred Dresselhaus'' was elected in 1974 as a member of National Academy of Engineering in List of members of the National Academy of Engineering (Electronics), Electronics, Communication & Information Systems Engineering and Materials Engineering for contributions to the experimental studies of metals and semimetals, and to education. (' Spiewak; November 11, 1930 – February 20, 2017), known as the "Queen of Carbon Science",Queen of Carbon Science ''U.S. News & World Report''. By Marlene Cimons, National Science Foundation. July 27, 2012. Retrieved August 14, 2012. w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Boris Altshuler
Boris Leonidovich Altshuler (russian: Бори́с Леонидович Альтшу́лер, born 27 January 1955, Saint Petersburg, Leningrad, Soviet Union, USSR) is a professor of theoretical physics at Columbia University. His specialty is theoretical condensed matter physics. Education and career Altshuler attended State Secondary School 489 in Saint Petersburg. He received his diploma in physics from Leningrad State University in 1976. Altshuler continued on at the Leningrad Institute for Nuclear Physics, where he was awarded his Ph.D. in physics in 1979. Altshuler stayed at the institute for the next ten years as a research fellow. In 1989, Altshuler joined the faculty of the Massachusetts Institute of Technology. While there, he received the Hewlett-Packard Europhysics Prize (now called the Agilent Physics Prize) and became a fellow of the American Physical Society. Altshuler left MIT in 1996 to take a professorship at Princeton University. While there, he became affiliat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mesoscopic Physics
Mesoscopic physics is a subdiscipline of condensed matter physics that deals with materials of an intermediate size. These materials range in size between the nanoscale for a quantity of atoms (such as a molecule) and of materials measuring micrometres. The lower limit can also be defined as being the size of individual atoms. At the micrometre level are bulk materials. Both mesoscopic and macroscopic objects contain many atoms. Whereas average properties derived from constituent materials describe macroscopic objects, as they usually obey the laws of classical mechanics, a mesoscopic object, by contrast, is affected by thermal fluctuations around the average, and its electronic behavior may require modeling at the level of quantum mechanics.Sci-Tech Dictionary. McGraw-Hill Dictionary of Scientific and Technical Terms. 2003. McGraw-Hill Companies, Inc A macroscopic electronic device, when scaled down to a meso-size, starts revealing quantum mechanical properties. For example, at ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
