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Resonant Tunnelling Diode
A resonant-tunneling diode (RTD) is a diode with a resonant-tunneling structure in which electrons can tunnel through some resonant states at certain energy levels. The current–voltage characteristic often exhibits negative differential resistance regions. All types of tunneling diodes make use of quantum mechanical tunneling. Characteristic to the current–voltage relationship of a tunneling diode is the presence of one or more negative differential resistance regions, which enables many unique applications. Tunneling diodes can be very compact and are also capable of ultra-high-speed operation because the quantum tunneling effect through the very thin layers is a very fast process. One area of active research is directed toward building oscillators and switching devices that can operate at terahertz frequencies. Introduction An RTD can be fabricated using many different types of materials (such as III–V, type IV, II–VI semiconductor) and different types of resonant tu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diode
A diode is a two-terminal electronic component that conducts current primarily in one direction (asymmetric conductance); it has low (ideally zero) resistance in one direction, and high (ideally infinite) resistance in the other. A diode vacuum tube or thermionic diode is a vacuum tube with two electrodes, a heated cathode and a plate, in which electrons can flow in only one direction, from cathode to plate. A semiconductor diode, the most commonly used type today, is a crystalline piece of semiconductor material with a p–n junction connected to two electrical terminals. Semiconductor diodes were the first semiconductor electronic devices. The discovery of asymmetric electrical conduction across the contact between a crystalline mineral and a metal was made by German physicist Ferdinand Braun in 1874. Today, most diodes are made of silicon, but other semiconducting materials such as gallium arsenide and germanium are also used. Among many uses, diodes are found in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nanohub
nanoHUB.org is a science and engineering gateway comprising community-contributed resources and geared toward education, professional networking, and interactive simulation tools for nanotechnology. Funded by the United States National Science Foundation (NSF), it is a product of the Network for Computational Nanotechnology (NCN). NCN supports research efforts in nanoelectronics; nanomaterials; nanoelectromechanical systems (NEMS); nanofluidics; nanomedicine, nanobiology; and nanophotonics. History The Network for Computational Nanotechnology was established in 2002 to create a resource for nanoscience and nanotechnology via online services for research, education, and professional collaboration. Initially a multi-university initiative of eight member institutions including Purdue University, the University of California at Berkeley, the University of Illinois at Urbana-Champaign, Massachusetts Institute of Technology, the Molecular Foundry at Lawrence Berkeley National Laborator ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leroy Chang
Leroy L. Chang (; 20 January 1936 – 10 August 2008) was an experimental physicist and solid state electronics researcher and engineer. Born in China, he studied in Taiwan and then the United States, obtaining his doctorate from Stanford University in 1963. As a research physicist he studied semiconductors for nearly 30 years at IBM's Thomas J. Watson Research Center, New York. This period included pioneering work on superlattice heterostructures with Nobel Prize-winning physicist Leo Esaki. In 1993, Chang moved from New York to Hong Kong, switching from industrial research into academia in anticipation of the 1997 transfer of the British colony to China. He was among the first wave of recruits to the Hong Kong University of Science and Technology. Over the following 14 years he helped build the university's reputation in his roles as Dean of Science, Professor of Physics, Vice-President for Academic Affairs, and Emeritus Professor. He retired in 2001. Honours bestowed on Ch ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leo Esaki
Reona Esaki (江崎 玲於奈 ''Esaki Reona'', born March 12, 1925), also known as Leo Esaki, is a Japanese physicist who shared the Nobel Prize in Physics in 1973 with Ivar Giaever and Brian David Josephson for his work in electron tunneling in semiconductor materials which finally led to his invention of the Esaki diode, which exploited that phenomenon. This research was done when he was with Tokyo Tsushin Kogyo (now known as Sony). He has also contributed in being a pioneer of the semiconductor superlattices. Early life and education Esaki was born in Takaida-mura, Nakakawachi-gun, Osaka Prefecture (now part of Higashiōsaka City) and grew up in Kyoto, near by Kyoto Imperial University and Doshisha University. He first had contact with American culture in . After graduating from the Third Higher School, he studied physics at Tokyo Imperial University, where he had attended Hideki Yukawa's course in nuclear theory in October 1944. Also, he lived through the Bombing of Tokyo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Raphael Tsu
Raphael Tsu (born December 27, 1931) is a Fellow of the American Physical Society and is Professor Emeritus of electrical engineering at the University of North Carolina at Charlotte, Charlotte, NC. Early life and education Tsu was born to a Catholic family in Shanghai, China, in 1931. As a child he was inspired by his great uncle who in 1926 was amongst the first six Chinese bishops ever to be consecrated at the Vatican in Rome and as a teenager by his US-educated father, Adrian, and French-educated uncle, Louis. His paternal grandfather and great uncle were pioneers in power plant and modern shipyard in Shanghai. While leaving Shanghai, his great uncle, on his death bed told him to remember the old Chinese saying that to succeed requires the right tool. Tsu initially emigrated to the west in 1952 to study physics at Medway Technical College in England for one year before leaving for Dayton, OH, the following year. He earned the bachelors of science at the University of Dayton ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quantum Tunneling
In physics, a quantum (plural quanta) is the minimum amount of any physical entity (physical property) involved in an interaction. The fundamental notion that a physical property can be "quantized" is referred to as "the hypothesis of quantization". This means that the magnitude of the physical property can take on only discrete values consisting of integer multiples of one quantum. For example, a photon is a single quantum of light (or of any other form of electromagnetic radiation). Similarly, the energy of an electron bound within an atom is quantized and can exist only in certain discrete values. (Atoms and matter in general are stable because electrons can exist only at discrete energy levels within an atom.) Quantization is one of the foundations of the much broader physics of quantum mechanics. Quantization of energy and its influence on how energy and matter interact (quantum electrodynamics) is part of the fundamental framework for understanding and describing nature. E ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Double Square Barrier Potential
A double is a look-alike or doppelgänger; one person or being that resembles another. Double, The Double or Dubble may also refer to: Film and television * Double (filmmaking), someone who substitutes for the credited actor of a character * ''The Double'' (1934 film), a German crime comedy film * ''The Double'' (1971 film), an Italian film * ''The Double'' (2011 film), a spy thriller film * ''The Double'' (2013 film), a film based on the Dostoevsky novella * '' Kamen Rider Double'', a 2009–10 Japanese television series ** Kamen Rider Double (character), the protagonist in a Japanese television series of the same name Food and drink * Doppio, a double shot of espresso * Dubbel, a strong Belgian Trappist beer or, more generally, a strong brown ale * A drink order of two shots of hard liquor in one glass * A "double decker", a hamburger with two patties in a single bun Games * Double, action in games whereby a competitor raises the stakes ** , in contract bridge ** Doubl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fermi Level
The Fermi level of a solid-state body is the thermodynamic work required to add one electron to the body. It is a thermodynamic quantity usually denoted by ''µ'' or ''E''F for brevity. The Fermi level does not include the work required to remove the electron from wherever it came from. A precise understanding of the Fermi level—how it relates to electronic band structure in determining electronic properties, how it relates to the voltage and flow of charge in an electronic circuit—is essential to an understanding of solid-state physics. In band structure theory, used in solid state physics to analyze the energy levels in a solid, the Fermi level can be considered to be a hypothetical energy level of an electron, such that at thermodynamic equilibrium this energy level would have a ''50% probability of being occupied at any given time''. The position of the Fermi level in relation to the band energy levels is a crucial factor in determining electrical properties. The Fermi le ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Van Der Pol Oscillator
In dynamical system, dynamics, the Van der Pol oscillator is a Conservative force, non-conservative oscillator with nonlinearity, non-linear Damping ratio, damping. It evolves in time according to the second-order differential equation: :-\mu(1-x^2)+x= 0, where ''x'' is the position coordinate system, coordinate—which is a function (mathematics), function of the time ''t'', and ''μ'' is a scalar (mathematics), scalar parameter indicating the nonlinearity and the strength of the damping. History The Van der Pol oscillator was originally proposed by the Dutch electrical engineering, electrical engineer and physicist Balthasar van der Pol while he was working at Philips. Van der Pol found stable oscillations, which he subsequently called relaxation oscillator, relaxation-oscillations and are now known as a type of limit cycle in electrical circuits employing vacuum tubes. When these circuits are driven near the limit cycle, they become entrainment (physics), entrained, i.e. the d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Liénard System
Liénard is a surname. Notable people with the surname include: * François Liénard de la Mivoye (1782–1862), French-Mauritian naturalist * Édouard Liénard (1779–1848), French painter *Alfred-Marie Liénard (1869–1958), French physicist and engineer * Michel Joseph Napoléon Liénard (1810–1870), sculptor from France *Daniel Liénard de Beaujeu, French officer during the Seven Years' War *Liénard–Wiechert potential The Liénard–Wiechert potentials describe the classical electromagnetic effect of a moving electric point charge in terms of a vector potential and a scalar potential in the Lorenz gauge. Stemming directly from Maxwell's equations, these descr ... describes the electromagnetic effect of a moving electric charge * Liénard equation, type of differential equation, after the French physicist Alfred-Marie Liénard {{DEFAULTSORT:Lienard ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
InAlAs
Aluminium indium arsenide, also indium aluminium arsenide or AlInAs ( Alx In1−x As), is a semiconductor material with very nearly the same lattice constant as GaInAs, but a larger bandgap. The ''x'' in the formula above is a number between 0 and 1 - this indicates an arbitrary alloy between InAs and AlAs. The formula ''AlInAs'' should be considered an abbreviated form of the above, rather than any particular ratio. Aluminium indium arsenide is used e.g. as a buffer layer in metamorphic HEMT transistors, where it serves to adjust the lattice constant differences between the GaAs substrate and the GaInAs channel. It can be also used to form alternate layers with indium gallium arsenide, which act as quantum wells; these structures are used in e.g. broadband quantum cascade lasers. Safety and toxicity aspects The toxicology of AlInAs has not been fully investigated. The dust is an irritant to skin, eyes and lungs. The environment, health and safety aspects of aluminium indium ars ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
InGaAs
Indium gallium arsenide (InGaAs) (alternatively gallium indium arsenide, GaInAs) is a ternary alloy (chemical compound) of indium arsenide (InAs) and gallium arsenide (GaAs). Indium and gallium are ( group III) elements of the periodic table while arsenic is a (group V) element. Alloys made of these chemical groups are referred to as "III-V" compounds. InGaAs has properties intermediate between those of GaAs and InAs. InGaAs is a room-temperature semiconductor with applications in electronics and photonics. The principal importance of GaInAs is its application as a high-speed, high sensitivity photodetector of choice for optical fiber telecommunications. Nomenclature Indium gallium arsenide (InGaAs) and gallium-indium arsenide (GaInAs) are used interchangeably. According to IUPAC standards the preferred nomenclature for the alloy is GaxIn1-xAs where the group-III elements appear in order of increasing atomic number, as in the related alloy system AlxGa1-xAs. By far, the m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
