nanoHUB.org Style Guide 1.5

by Margaret Shepard Morris

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1 = '''nanoHUB.org Style Guide and Glossary 1.0''' =
2
3 In general, nanoHUB style adheres to ''The Chicago Manual of Style'', 15th Ed. (CMS), and ''IEEE Standards Style Manual'' (IEEE) to resolve questions of style and usage on nanoHUB.org
4
5 CMS and IEEE styles evolve with the advent of new technologies, genres, and conventions; for this reason, these guidelines are used by the nanoHUB editors to resolve questions of style throughout the website. Familiarity with CMS, then, is key also to maintaining consistency in nanoHUB materials, which are frequently written by multiple authors possessing different bases for style. In other words, when in doubt, see CMS or IEEE manuals.
6
7 Since the style manuals do not account for each particular of evolving terminology in the nano science and nanotechnology community, the NCN Editorial Team has compiled a nanoHUB Glossary for additional information on spelling, hyphenation, and capitalization of field-specific terms.
8 The Glossary represents the best editorial attempt to research how terms are used in the field and to represent them in such a way as to clarify language usage for nanoHUB users. Perhaps the glossary may also serve to help codify terms in the world of nano science communications.
9 The nanoHUB Style Guide and Glossary 1.0 is separated into the following sections: General Guidelines, Specific Guidelines, and the Glossary.
10
11 == General Guidelines ==
12 '''Audience consideration and informational density of a document''': In drafting and revising documents/texts for nanoHUB.org, authors must keep their intended audience in mind. The density of information in a document must be appropriate for the audience. If a document is intended for multiple or mixed audiences (readers of different competencies and literacies), then authors must take care to tailor sections for those multiple or mixed audiences. The following table offers general guidelines.
13
14 ||'''Feature of the document'''||'''Layperson/Undergraduate'''||''' Managerial/Graduate'''||'''Expert'''||
15 ||''Introduction''||Relevance||Problem/Solution||Technical||
16 ||''Mathematical models''||Avoid||Avoid||OK||
17 ||''Equations''||Avoid||Simple/Avoid||OK||
18 ||''Graphics''||Generally illustrative||Simple, presentational||Detailed, analytical||
19 ||''Detail level''||Simple, narrative||General, accurate||Accurate, numerical||
20 ||''Technical terms||General, illustratrive||Administrative||Expert, technical||
21 ||''Emphasis||Informational, interest||Operations, costs||Analysis||
22
23 In relation to the taxonomy of materials here at nanoHUB based on undergraduate and graduate education, authors can demonstrate consideration of the audience by using the appropriate level of detail. For example, the composition of a First-Time Users' Guide undergraduates will be most suited to the audience if the introduction of the document clearly states the relevance of the material to the readers' interests, mathematical models and equations are kept to a minimum, if not avoided entirely, any graphics are illustrative of points made clearly in the text, the detail level is kept simple and focused on providing a narrative, technical terms are carefully introduced by using the full English term at the first instance with a full description or definition, and only then using abbreviations.
24
25 +
==Style Guide==
26
27 ==Glossary==
28 revised June 12, 2009
29
30 A helpful site:
31
32 '''1-D''', '''2-D''', '''3-D''', or '''one-dimensional''', etc. (hyphenated form is the standard?)
33
34 '''ab initio''' (Latin, "from the beginning"). Italicize. Hyphenate when used as an adjective, i. e. the ab-initio process
35
36 '''ABACUS''': Assembly of Basic Applications for Coordinated Understanding of Semiconductor Devices
37
38 ACUTE: Assembly for Computational Electronics
39
40 AQME: Advancing Quantum Mechanics of Engineers
41
42 aTCADlab: A Technology Computer Aided Design Lab
43
44 applied bias: the voltage applied to the structure
45 See
46
47 atomic force microscope: The atomic force microscope (AFM) or scanning force microscope (SFM) is a very high-resolution type of scanning probe microscopy, with demonstrated resolution of fractions of a nanometer, more than 1000 times better than the optical diffraction limit. The precursor to the AFM, the scanning tunneling microscope, was developed by Gerd Binnig and Heinrich Rohrer in the early 1980s, a development that earned them the Nobel Prize for Physics in 1986. Binnig, Quate and Gerber invented the first AFM in 1986. The AFM is one of the foremost tools for imaging, measuring and manipulating matter at the nanoscale. The information is gathered by "feeling" the surface with a mechanical probe. Piezoelectric elements that facilitate tiny but accurate and precise movements on (electronic) command enable the very precise scanning.
48 See
49
50 ballistic nanotransistor: a transistor with minimal impediment to speed of current
51
52 ballistic transport: the transport of electrons in a medium with negligible electrical resistivity due to scattering. Without scattering, electrons simply obey Newton's second law of motion at non-relativistic speeds.
53 See
54
55 band structure: In solid-state physics, the electronic band structure (or simply band structure) of a solid describes ranges of energy that an electron is "forbidden" or "allowed" to have. It is due to the diffraction of the quantum mechanical electron waves in the periodic crystal lattice. The band structure of a material determines several characteristics, in particular its electronic and optical properties.
56 See
57
58 bandgap: the range of energies between existing energy bands where no energy levels exist
59 See
60
61 Bauschinger effect: The Bauschinger effect refers to a property of materials where the material's stress/strain characteristics change as a result of the microscopic stress distribution of the material. For example, an increase in tensile yield strength occurs at the expense of compressive yield strength.
62 The Bauschinger effect is named after the German engineer Johann Bauschinger.
63 See
64
65 bipolar junction transistors
66
67
68 biomedical engineering: the application of engineering principles and techniques to the medical field. It combines the design and problem solving skills of engineering with medical and biological sciences to improve healthcare diagnosis and treatment.
69 See
70
71 biosensing:
72
73 biosensor: A biosensor is a device for the detection of an analyte that combines a biological component with a physicochemical detector component.
74 It consists of 3 parts: (1) the sensitive biological element (biological material (eg. tissue, microorganisms, organelles, cell receptors, enzymes, antibodies, nucleic acids, etc), a biologically derived material or biomimic) The sensitive elements can be created by biological engineering. (2) the transducer or the detector element (works in a physicochemical way; optical, piezoelectric, electrochemical, etc.) that transforms the signal resulting from the interaction of the analyte with the biological element into another signal (i.e., transducers) that can be more easily measured and quantified; (3) associated electronics or signal processors that is primarily responsible for the display of the results in a user-friendly way.
75 See
76
77 bipolar junction transistor (BJT): a type of transistor. It is a three-terminal device constructed of doped semiconductor material and may be used in amplifying or switching applications. Bipolar transistors are so named because their operation involves both electrons and holes, as opposed to unipolar transistors, such as field-effect transistors, in which only one carrier type is involved in charge flow. Although a small part of the transistor current is due to the flow of majority carriers, most of the transistor current is due to the flow of minority carriers and so BJTs are classified as minority-carrier devices.
78 See
79
80 Boltmann transport equation (BTE):
81
82 bound state: In physics, a bound state is a composite of two or more building blocks (particles or bodies) that behaves as a single object. In quantum mechanics (where the number of particles is conserved), a bound state is a state in the Hilbert space that corresponds to two or more particles whose interaction energy is negative, and therefore these particles cannot be separated unless energy is spent. The energy spectrum of a bound state is discrete, unlike the continuous spectrum of isolated particles. (Actually, it is possible to have unstable bound states with a positive interaction energy provided that there is an "energy barrier" that has to be tunnelled through in order to decay. This is true for some radioactive nuclei and for some electret materials able to carry electric charge for rather long periods.)
83 In general, a stable bound state is said to exist in a given potential of some dimension if stationary wavefunctions exist (normalized in the range of the potential). The energies of these wavefunctions are negative.
84 See
85
86 Bravais lattice: any of 14 possible three-dimensional configurations of points used to describe the orderly arrangement of atoms in a crystal. Each point represents one or more atoms in the actual crystal, and if the points are connected by lines, a crystal lattice is formed; the lattice is divided into a number of identical blocks, or unit cells, characteristic of the Bravais lattices. The French scientist Auguste Bravais demonstrated in 1850 that only these 14 types of unit cells are compatible with the orderly arrangements of atoms found in crystals.
87 See
88
89 bulk: back contact of a MOSFET also referred to as a substrate contact
90 See
91
92 bulk band structure
93
94 bulk semiconductors: Frequently distinguished from mutiple quantum well (MQW) semiconductors by their single crystals and conventional heterojunction structures.
95 See "Bulk Semiconductors" in Applied Optics 26.2 (1987): 214.
96
97 Burgers vector: often denoted by b, is a vector that represents the magnitude and direction of the lattice distortion of dislocation in a crystal lattice.
98 See
99
100 capacitance: charge per unit voltage
101 See
102
103 capacitor: a passive electronic component consisting of a pair of conductors separated by a dielectric. When a voltage potential difference exists between the conductors, an electric field is present in the dielectric. This field stores energy and produces a mechanical force between the plates. The effect is greatest between wide, flat, parallel, narrowly separated conductors.
104 See
105
106 carbon nanotubes: 100 amps of electricity crackle in a vacuum chamber, creating a spark that transforms carbon vapor into tiny structures. Depending on the conditions, these structures can be shaped like little, 60-atom soccer balls, or like rolled-up tubes of atoms, arranged in a chicken-wire pattern, with rounded ends. These tiny, carbon nanotubes, discovered by Sumio Iijima at NEC labs in 1991, have amazing properties. They are 100 times stronger than steel, but weigh only one-sixth as much! They are incredibly resilient under physical stress; even when kinked to a 120-degree angle, they will bounce back to their original form, undamaged. And they can carry electrical current at levels that would vaporize ordinary copper wires.
107 See
108
109 charge carriers: In physics, a charge carrier denotes a free (mobile, unbound) particle carrying an electric charge. Examples are electrons and ions.
110 See
111
112 chiralities: a property of asymmetry important in several branches of science. An object or a system is chiral if it cannot be superposed on its mirror image. A chiral object and its mirror image are called enantiomorphs (Greek opposite forms) or, when referring to molecules, enantiomers. A non-chiral object is called achiral (sometimes also amphichiral) and can be superposed on its mirror image.
113 See
114
115 CMOS: complimentary metal oxide silicon (transistor)
116 See
117
118 computational chemistry: a branch of chemistry that uses computers to assist in solving chemical problems. It uses the results of theoretical chemistry, incorporated into efficient computer programs, to calculate the structures and properties of molecules and solids. While its results normally complement the information obtained by chemical experiments, it can in some cases predict hitherto unobserved chemical phenomena. It is widely used in the design of new drugs and materials.
119 See
120
121 computational electronics: refers to the physical simulation of semiconductor devices in terms of charge transport and the corresponding electrical behavior. It is related to, but usually separate from process simulation, which deals with various physical processes such as material growth, oxidation, impurity diffusion, etching, and metal deposition inherent in device fabrication leading to integrated circuits. Device
122 simulation can be thought of as one component of technology for computer-aided design (TCAD), which provides a basis for device modeling, which deals with compact behavioral models for devices and subcircuits relevant for circuit simulation in commercial packages such as SPICE.
123 See Chapter 1 of Dragica Vasileska's Computational Electronics
124
125 computational engineering: a relatively new discipline of engineering. It is typically offered as a masters or doctorate program at several institutions. This is not to be confused with computer engineering (related to building computers).
126 See
127
128 computational materials (context?)
129
130 computational science: Computational science (or scientific computing) is the field of study concerned with constructing mathematical models and numerical solution techniques and using computers to analyze and solve scientific, social scientific and engineering problems. In practical use, it is typically the application of computer simulation and other forms of computation to problems in various scientific disciplines.
131 See
132
133 crystals: materials in which atoms are placed in a highly ordered structure. Materials that are not crystals are amorphous.
134 See
135
136 CV measurement: capacitance versus voltage measurement
137 See
138
139 depassivation
140
141 depletion: removal of free carriers in a semiconductor
142 See
143
144 depletion region: In semiconductor physics, the depletion region, also called depletion layer, depletion zone, junction region or the space charge region, is an insulating region within a conductive, doped semiconductor material where the charge carriers have diffused away, or have been forced away by an electric field.
145 See
146
147 device physics:
148
149 dielectric: a nonconducting substance, i.e. an insulator. Although "dielectric" and "insulator" are generally considered synonymous, the term "dielectric" is more often used to describe the insulating material between the metallic plates of a capacitor, while "insulator" is more often used when the material is being used to prevent a current flow across it.
150 See
151
152 drain: contact region of a MOSFET to which the electrons in the channel flow
153 See
154
155 drift: the motion of carriers caused by an electric field
156
157
158 drift-diffusion model: model of a semiconductor is frequently used to describe semiconductor devices. The assumptions of the simplified drift-diffusion model are: full ionization: all dopants are assumed to be ionized (shallow dopants); non-degenerate: the Fermi energy is assumed to be at least 3 kT below/above the conduction/valence band edge; steady state: All variables are independent of time; constant temperature: the temperature is constant throughout the device. See
159
160 double-gate: same as dual-gate
161
162 dual-gate: having two gates; see gate
163
164 E=kinetic energy
165
166 E(k), E-k: relation of kinetic energy and momentum vector, use the formula E(k).
167
168 ED: electron density
169
170 effective mass: In solid state physics, a particle's effective mass is the mass it seems to carry in the semiclassical model of transport in a crystal. It can be shown that electrons and holes in a crystal respond to electric and magnetic fields almost as if they were particles with a mass dependent upon the their direction of travel, an effective mass tensor.
171 The effective mass has important effects on the properties of a solid, including everything from the efficiency of a solar cell to the speed of an integrated circuit.
172 See
173
174 eigenfunctions: In mathematics, an eigenfunction of a linear operator, A, defined on some function space is any non-zero function f in that space that returns from the operator exactly as is, except for a multiplicative scaling factor. More precisely, one has for some scalar, λ, the corresponding eigenvalue.
175 See
176
177 eigenstates: (quantum mechanics) A dynamical state whose state vector (or wave function) is an eigenvector (or eigenfunction) of an operator corresponding to a specified physical quantity.
178
179 eigenvalues: a special set of scalars associated with a linear system of equations (i.e., a matrix equation) that are sometimes also known as characteristic roots, characteristic values (Hoffman and Kunze 1971), proper values, or latent roots (Marcus and Minc 1988, p. 144).
180
181 The determination of the eigenvalues and eigenvectors of a system is extremely important in physics and engineering, where it is equivalent to matrix diagonalization and arises in such common applications as stability analysis, the physics of rotating bodies, and small oscillations of vibrating systems, to name only a few. Each eigenvalue is paired with a corresponding so-called eigenvector (or, in general, a corresponding right eigenvector and a corresponding left eigenvector; there is no analogous distinction between left and right for eigenvalues).
182 See
183
184 E-k: What is the natural language version of this relationship [k=momentum vector, as below? E=? [mc^2?]
185
186 energy bands: a collection of closely space energy levels
187 See
188
189 energy levels: A quantum mechanical system or particle that is bound, confined spatially, can only take on certain discrete values of energy, as opposed to classical particles, which can have any energy. These values are called energy levels. The term is most commonly used for the energy levels of electrons in atoms or molecules, which are bound by the electric field of the nucleus. The energy spectrum of a system with energy levels is said to be quantized.
190 See
191
192 energy states: also called energy level
193
194 Fermi level: The Fermi level is an energy that pertains to electrons in a semiconductor. It is the chemical potential μ that appears in the electrons' Fermi-Dirac distribution function, [formula] which is the probability that there is an electron in a particular single-particle state with energy. T is the absolute temperature and k is Boltzmann's constant.
195 See Wikipedia for formula .
196
197 Fermions: Particles such as electrons, protons, and neutrons that are the "constituents" of matter and account for its impenetrability. Other particles -- called, "bosons" -- mediate, or carry, forces between fermions. Examples would be photons, gravitons, and gluons.
198 See
199
200 field-effect transistor (FET): a type of transistor that relies on an electric field to control the shape and hence the conductivity of a channel of one type of charge carrier in a semiconductor material. FETs are sometimes called unipolar transistors to contrast their single-carrier-type operation with the dual-carrier-type operation of bipolar (junction) transistors (BJT). The concept of the FET predates the BJT, though it was not physically implemented until after BJTs due to the limitations of semiconductor materials and relative ease of manufacturing BJTs compared to FETs at the time.
201 See
202
203 fully coupled
204
205 fully-depleted (FD):
206
207 G: kinetic energy
208
209 gate: electrode of a FET, which controls the charge in the channel; see logic gate
210
211
212 graphene: a one-atom-thick planar sheet of sp2-bonded carbon atoms that are densely packed in a honeycomb crystal lattice. It can be viewed as an atomic-scale chicken wire made of carbon atoms and their bonds. The name comes from GRAPHITE + -ENE; graphite itself consists of many graphene sheets stacked together.
213 See
214
215 heterojunction: the interface that occurs between two layers or regions of dissimilar crystalline semiconductors. These semiconducting materials have unequal band gaps as opposed to a homojunction.
216
217 intraband:
218
219 ion channels: pore-forming proteins that help establish and control the small voltage gradient across the plasma membrane of all living cells (see cell potential) by allowing the flow of ions down their electrochemical gradient. They are present in the membranes that surround all biological cells.
220 See
221
222 intervalley:
223
224 IV characteristics: Current-Voltage characteristics
225 See
226 I-V curve: current-voltage curve
227 Are we dealing with current as a function of voltage?
228
229 k= momentum vector
230
231 Kronig-Penney: a simple approximation of a solid
232
233 lamellae: a term for a platelike structure, appearing in multiples, that occurs in various situations, such as biology or materials sciences. It implies a thin layer (Latin), the same derivation as for `laminate'.
234 See
235
236 lamellar: Lamellar structures or microstructures are composed of fine, alternating layers of different materials in the form of lamellae. They are often observed in cases where a phase transformation front moves quickly, leaving behind two solid products, as in rapid cooling of eutectic (such as solder) or eutectoid (such as pearlite) systems.
237 See
238
239 Laplacian: In mathematics and physics, the Laplace operator or Laplacian, denoted by or and named after Pierre-Simon de Laplace, is a differential operator, specifically an important case of an elliptic operator, with many applications. In physics, it is used in modeling of wave propagation, heat flow and forming the Helmholtz equation. It is central in electrostatics and fluid mechanics, anchoring in Laplace's equation and Poisson's equation. In quantum mechanics, it represents the kinetic energy term of the Schrödinger equation. In mathematics, functions with vanishing Laplacian are called harmonic functions; the Laplacian is at the core of Hodge theory and the results of de Rham cohomology. In image processing domain it is used for detecting edges.
240 See
241
242 Lennard-Jones potential: (also referred to as the LJ potential, 6-12 potential or, less commonly, 12-6 potential) is a mathematically simple model that describes the interaction between a pair of neutral atoms or molecules. It was proposed in 1924 by John Lennard-Jones.
243 The LJ potential is of the form
244 ,
245 where is the depth of the potential well and is the (finite) distance at which the interparticle potential is zero and r is the distance between the particles.
246 See
247
248 logic gate: A logic gate performs a logical operation on one or more logic inputs and produces a single logic output. The logic normally performed is Boolean logic and is most commonly found in digital circuits. Logic gates are primarily implemented electronically using diodes or transistors, but can also be constructed using electromagnetic relays, fluidics, optics, molecules, or even mechanical elements.
249 In electronic logic, a logic level is represented by a voltage or current, (which depends on the type of electronic logic in use). Each logic gate requires power so that it can source and sink currents to achieve the correct output voltage. In logic circuit diagrams the power is not shown, but in a full electronic schematic, power connections are required.
250 See
251
252 madFET: many acronym device field effect transistor
253
254 majority carriers: more abundant charge carriers
255
256 material properties
257
258 MATLAB: stands for matrix laboratory, is a numerical computing environment and fourth generation programming language
259 See
260
261 material science: Nanotechnology bears the promise of engineering at an atomic scale--of assembling atoms in arrangements that are completely unnatural, thereby creating materials with properties that have never been seen before. This may sound like science fiction, but it has been going on for more than 30 years, since the invention of Molecular Beam Epitaxy (MBE). MBE provides a way of growing a block of material one sheet of atoms at a time. By mixing different types of atoms in various combinations, it is possible to "tune" the properties of the resulting material. For example, the laser diode in your CD player is probably made from silicon. It shines a particular wavelength of light based on the energy gap between the conduction and valence bands in silicon. That same laser diode could be "tuned" to emit a different wavelength by building it with a new material engineered to have a different band gap.
262 See
263
264 metamaterials: exotic composite materials that display properties beyond those available in naturally occurring materials. Instead of constructing materials at the chemical level, as is ordinarily done, these are constructed with two or more materials at the macroscopic level. One of their defining characteristics is that the electromagnetic response results from combining two or more distinct materials in a specified way which extend the range of electromagnetic patterns because of the fact that they are not found in nature.
265 See
266
267 microelectronics: Microelectronics is a subfield of electronics. Microelectronics, as the name suggests, is related to the study and manufacture, or microfabrication, of electronic components which are very small (usually micrometre-scale or smaller, but not always). These devices are made from semiconductors. Many components of normal electronic design are available in microelectronic equivalent: transistors, capacitors, inductors, resistors, diodes and of course insulators and conductors can all be found in microelectronic devices.
268 See
269
270 microfabrication: (also micromanufacturing) term to describe processes of fabrication of miniature structures, of micrometre sizes and smaller. Historically the earliest micromanufacturing was used for semiconductor devices in integrated circuit fabrication and these processes have been covered by the term "semiconductor device fabrication," "semiconductor manufacturing," etc. Practical advances in microelectromechanical systems (MEMS) and other nanotechnology, where the technologies from IC fabrication are being re-used, adapted or extended have led to the extension of the scope and techniques of microfabrication.
271 Miniaturization of various devices presents challenges in many areas of science and engineering: physics, chemistry, material science, computer science, ultra-precision engineering, fabrication processes, and equipment design. It is also giving rise to various kinds of interdisciplinary research.
272 The major concepts and principles of micromanufacturing are laser technology, microlithography, micromechatronics, micromachining and microfinishing (nanofinishing).
273 See
274
275 minority carriers: less abundant charge carriers
276
277 miscut: a cut that does not follow a plane
278
279
280 MO theory (Molecular Orbital Theory): In chemistry, molecular orbital theory (MO theory) is a method for determining molecular structure in which electrons are not assigned to individual bonds between atoms, but are treated as moving under the influence of the nuclei in the whole molecule. In this theory, each molecule has a set of molecular orbitals, in which it is assumed that the molecular orbital wave function ψf may be written as a simple weighted sum of the n constituent atomic orbitals χi, according to the following equation:
281 See
282
283 modulator:
284
285 molecular dynamics: a form of computer simulation in which atoms and molecules are allowed to interact for a period of time by approximations of known physics, giving a view of the motion of the atoms. Because molecular systems generally consist of a vast number of particles, it is impossible to find the properties of such complex systems analytically.
286 See
287
288 molecular electronics: Molecular electronics (sometimes called moletronics) is an interdisciplinary theme that spans physics, chemistry, and materials science. The unifying feature of this area is the use of molecular building blocks for the fabrication of electronic components, both passive (e.g. resistive wires) and active (e.g. transistors). The concept of molecular electronics has aroused much excitement both in science fiction and among scientists due to the prospect of size reduction in electronics offered by molecular-level control of properties. Molecular electronics provides means to extend Moore's Law beyond the foreseen limits of small-scale conventional silicon integrated circuits.
289 See
290
291 molecular mechanism
292
293 molecular orbital: In chemistry, a molecular orbital (or MO) is a mathematical function that describes the wave-like behavior of an electron in a molecule. This function can be used to calculate chemical and physical properties such as the probability of finding an electron in any specific region. The use of the term "orbital" was first used in English by Robert S. Mulliken in 1925 as the English translation of Schrödinger's use of the German word Eigenfunktion. It has since been equated with the "region" generated with the function. Molecular orbitals are usually constructed by combining atomic orbitals or hybrid orbitals from each atom of the molecule, or other molecular orbitals from groups of atoms. They can be quantitatively calculated using the Hartree-Fock or Self-Consistent Field method.
294 See
295
296 molecular simulations
297
298 MOS: metal-oxide-silicon or metal-oxide-semiconductor (see the about page for Schred).
299
300 MOSCAP: metal-oxide-silicon capacitor
301
302 MOSFET: The metal–oxide–semiconductor field-effect transistor (MOSFET, MOS-FET, or MOS FET) is a device used to amplify or switch electronic signals. The MOSFET includes a channel of n-type or p-type semiconductor material (see article on semiconductor devices), and is accordingly called an NMOSFET or a PMOSFET (also commonly nMOS, pMOS). It is by far the most common transistor in both digital and analog circuits, though the bipolar junction transistor was at one time much more common.
303 See
304
305 MolST: Molecular Structure Tracer
306
307 multiscale models: Nanotechnology sometimes involves mixing something very small into a larger, more conventional system. For example, mixing carbon nanotubes into a conventional polymer gives it added strength. Or, using a carbon nanotube as the channel between two larger, source-drain contacts creates a transistor with improved channel mobility. But simulating such systems becomes a huge challenge. The smaller parts of the system must be solved with great accuracy–for example, by simulating each atom within a carbon nanotube. But the same approach can't possibly be applied to the larger system–for example, to each atom in the thousands of polymer molecules in a realistic sample–or the whole problem would be too big to solve!
308 Multi-scale methods attempt to solve the problem by stitching together smaller domains (where atomistic models apply) and larger domains (where continuum models apply) into a coherent solution.
309 See
310
311 multi-well: see well
312
313 n-type semiconductor: An N-type semiconductor (N for Negative) is obtained by carrying out a process of doping, that is, by adding an impurity of valence-five elements to a valence-four semiconductor in order to increase the number of free charge carriers (in this case negative).
314 When the doping material is added, it gives away (donates) weakly-bound outer electrons to the semiconductor atoms. This type of doping agent is also known as donor material since it gives away some of its electrons.
315 See
316
317 NAND chain (or nand-chain): NAND= not and
318
319 nand gate: a gate using not/and
320
321 nano electro-mechanical system: Nano Electro-Mechanical Systems (NEMS) are tiny machines built at the nanometer scale. Current NEMS applications are simple machines, such as the tiny cantilever shown at the right. An electrical circuit measures the deflection of the lever. A larger version of this device, with dimensions at the micrometer or millimeter scale, is commonly used as an airbag sensor in automobiles. A sudden stop causes a strong deflection of the lever, which signals that the airbags should be deployed. At the nano scale, such a lever is sensitive enough to measure the weight of individual atoms or molecules resting upon it!
322 See
323
324 nanoelectronics: Progress in technology has brought microelectronics to the nanoscale, but nanoelectronics is not yet a well-defined engineering discipline with a coherent, experimentally-verified, theoretical framework. The NCN has a vision for a new, 'bottom-up' approach to electronics, by which we mean understanding electronic conduction at the atomistic level, formulating new simulation techniques, developing a new generation of software tools, and bringing this new understanding and perspective into the classroom. We address problems in atomistic phenomena, quantum transport, percolative transport in inhomogeneous media, reliability, and the connection of nanoelectronics to new problems such as biology, medicine, and energy. We work closely with experimentalists to understand nanoscale phenomena and to explore new device concepts. In the course of this work, we produce open source software tools and educational resources that we share with the community through the nanoHUB.
325
326 nanomedicine: the medical application of nanotechnology. The approaches to nanomedicine range from the medical use of nanomaterials, to nanoelectronic biosensors, and even possible future applications of molecular nanotechnology. Current problems for nanomedicine involve understanding the issues related to toxicity and environmental impact of nanoscale materials.
327 see
328
329 nanoparticles: a small object that behaves as a whole unit in terms of its transport and properties. It is further classified according to size: In terms of diameter, fine particles cover a range between 100 and 2500 nanometers, while ultrafine particles, on the other hand, are sized between 1 and 100 nanometers. Similarly to ultrafine particles, nanoparticles are sized between 1 and 100 nanometers, though the size limitation can be restricted to two dimensions. Nanoparticles may or may not exhibit size-related properties that differ significantly from those observed in fine particles or bulk materials.
330 See
331
332 nanophotonics: the study of the behavior of light on the nanometre scale. It is considered as a branch of optical engineering which deals with optics, or the interaction of light with particles or substances, at deeply subwavelength length scales. Technologies in the realm of nano-optics include near-field scanning optical microscopy (NSOM), photoassisted scanning tunnelling microscopy, and surface plasmon optics.
333 See
334
335 When optical components are reduced to the nano scale, they exhibit interesting properties that can be harnessed to create new devices. For example, imagine a block of material with thin layers of alternating materials. This creates a periodic arrangement of alternating dielectric constants, forming a "photonic crystal" analogous to the electronic crystals used in semiconductor devices. Photonic crystals, along with quantum dots and other devices patterned at the nano scale, may form the basis for sensors and switches used in computers and telecommunications.
336 See
337
338 nanoscale: refering to structures between 1-100 nanometers (sometimes, more formally termed 'nanometer scale')
339
340 nanoscale entity: used to describe objects on the nanoscale; considered by some to be more acceptable that nanothing
341
342 Nanosphere (also Nanosphere, Inc.): a company that has no relation to nanoHUB.org
343
344 NanoSphere®: a textile product created by Schoeller Textiles
345
346 nanostructured surfaces: materials with microstructures modulated in zero to three dimensions on length scales less than 100nm
347 See "Advanced Nanotechnology Thin Film Approaches for the Food and Medical Industry: an overview of current status" by Vasco Teixera
348
349 nanotechnology: the study of the control of matter on an atomic and molecular scale. Generally nanotechnology deals with structures of the size 100 nanometers or smaller, and involves developing materials or devices within that size. Nanotechnology is very diverse, ranging from novel extensions of conventional device physics, to completely new approaches based upon molecular self-assembly, to developing new materials with dimensions on the nanoscale, even to speculation on whether we can directly control matter on the atomic scale.
350 See
351
352 nanothing: a zingier, happier [and more childish?] alternative to nanoscale entity
353
354 nanotube: a nanometer-scale tube-like structure
355 See
356
357 nanotransistors: a nanoscale transistor
358
359 nanowire: A nanowire is a nanostructure, with the diameter of the order of a nanometer (10−9 meters). Alternatively, nanowires can be defined as structures that have a thickness or diameter constrained to tens of nanometers or less and an unconstrained length. At these scales, quantum mechanical effects are important — hence such wires are also known as "quantum wires".
360 See
361
362 Nanowire: Nanowire is a simulation tool for of silicon nanowire FETs in the nanometer regime (diameter <= 5 nm) where quantum effects are important and (channel length <= 10 nm) where transport is mostly ballistic in nature.
363 See
364
365 NCN Supported
366
367 NCN@Purdue Supported
368
369 NEGF: The non-equilibrium Greens function (NEGF) formalism provides a powerful conceptual and computational framework for treating quantum transport in nanodevices. It goes beyond the Landauer approach for ballistic, non-interacting electronics to include inelastic scattering and strong correlation effects at an atomistic level.
370 See
371
372 NEMS/MEMS: Nanoelectromechanical systems (NEMS) are microelectromechanical systems (MEMS) with dimensions in the submicron region. Carbon nanotubes, whose dimensions can be several nanometers, are good examples of nanostructures that can be used in NEMS.
373
374 NOR chain: a chain using NOR operator
375
376 observables: results that can be directly observed instead of being inferred
377
378 OMEN: OMEN is also a fully parallelized using message passing interface(MPI) for wave vectors in the bandstructure and energy grids in the transport. Great flexibility in OMEN Nanowire for device structure and simulation options allows users to simulate a circular or rectangular nanowire with or without strain effect.
379
380 on-state:
381
382 Orowan loops
383
384 p-type semiconductor: A P-type semiconductor (P for Positive) is obtained by carrying out a process of doping, that is adding a certain type of atoms to the semiconductor in order to increase the number of free charge carriers (in this case positive).
385 When the doping material is added, it takes away (accepts) weakly-bound outer electrons from the semiconductor atoms. This type of doping agent is also known as acceptor material and the vacancy left behind by the electron is known as a hole.
386 See
387
388 PADRE (Pisces And Device REplacement)
389
390 passivation: the process of making a material "passive" in relation to another material prior to using the materials together. For example, prior to storing hydrogen peroxide in an aluminium container, the container can be passivated by rinsing it with a dilute solution of nitric acid and peroxide alternating with deionized water. The nitric acid and peroxide oxidizes and dissolves any impurities on the inner surface of the container, and the deionized water rinses away the acid and oxidized impurities. Another typical passivation process of cleaning stainless steel tanks involves cleaning with sodium hydroxide and citric acid followed by nitric acid (up to 20% at 120 °F) and a complete water rinse. This process will restore the film, remove metal particles, dirt, and welding-generated compounds (e.g. oxides).
391 In the context of corrosion, passivation is the spontaneous formation of a hard non-reactive surface film that inhibits further corrosion. This layer is usually an oxide or nitride that is a few atoms thick.
392 See
393
394 parallel computing: a form of computation in which many calculations are carried out simultaneously, operating on the principle that large problems can often be divided into smaller ones, which are then solved concurrently ("in parallel"). There are several different forms of parallel computing: bit-level, instruction level, data, and task parallelism. Parallelism has been employed for many years, mainly in high-performance computing, but interest in it has grown lately due to the physical constraints preventing frequency scaling. As power consumption (and consequently heat generation) by computers has become a concern in recent years, parallel computing has become the dominant paradigm in computer architecture, mainly in the form of multicore processors.
395 See
396
397 parallel programming: A parallel programming model is a set of software technologies to express parallel algorithms and match applications with the underlying parallel systems. It encloses the areas of applications, programming languages, compilers, libraries, communications systems, and parallel I/O. Due to the difficulties in automatic parallelization today, people have to choose a proper parallel programming model or a form of mixture of them to develop their parallel applications on a particular platform.
398 See
399
400 periodic potential: particle in a one-dimentional lattice
401
402 piecewise: In mathematics, a piecewise-defined function (also called a piecewise function) is a function whose definition is dependent on the value of the independent variable. Mathematically, a real-valued function f of a real variable x is a relationship whose definition is given differently on disjoint subsets of its domain (known as subdomains).
403 The word piecewise is also used to describe any property of a piecewise-defined function that holds for each piece but may not hold for the whole domain of the function. A function is piecewise differentiable or piecewise continuously differentiable if each piece is differentiable throughout its domain. In convex analysis, the notion of a derivative may be replaced by that of the subderivative for piecewise functions. Although the "pieces" in a piecewise definition need not be intervals, a function is not called "piecewise linear" or "piecewise continuous" or "piecewise differentiable" unless the pieces are intervals.
404 See
405
406 pn junction: a junction between an n-type and a p-type semiconductor
407 See
408
409 Prophet/PROPHET: a general PDE solver; suitable for continuum-based simulations of semiconductor and nano-bio devices
410
411 quantum: In physics, a quantum (plural: quanta) is an indivisible entity of a quantity that has the same units as the Planck constant and is related to both energy and momentum of elementary particles of matter (called fermions) and of photons and other bosons. The word comes from the Latin "quantus", for "how much." Behind this, one finds the fundamental notion that a physical property may be "quantized", referred to as "quantization". This means that the magnitude can take on only certain discrete numerical values, rather than any value, at least within a range. There is a related term of quantum number.
412 A photon is often referred to as a "light quantum". The energy of an electron bound to an atom (at rest) is said to be quantized, which results in the stability of atoms, and of matter in general. But these terms can be a little misleading, because what is quantized is this Planck's constant quantity whose units can be viewed as either energy multiplied by time or momentum multiplied by distance.
413 Usually referred to as quantum "mechanics", it is regarded by virtually every professional physicist as the most fundamental framework we have for understanding and describing nature at the infinitesimal level, for the very practical reason that it works. It is "in the nature of things", not a more or less arbitrary human preference.
414 See
415
416 quantum chemistry: a branch of theoretical chemistry, which applies quantum mechanics and quantum field theory to address issues and problems in chemistry. The description of the electronic behavior of atoms and molecules as pertaining to their reactivity is one of the applications of quantum chemistry. Quantum chemistry lies on the border between chemistry and physics, and significant contributions have been made by scientists from both fields. It has a strong and active overlap with the field of atomic physics and molecular physics, as well as physical chemistry.
417 See
418
419 quantum computing: a device for computation that makes direct use of quantum mechanical phenomena, such as superposition and entanglement, to perform operations on data. The basic principle behind quantum computation is that quantum properties can be used to represent data and perform operations on these data.
420 See
421
422 quantum dots: Quantum dots have a small, countable number of electrons confined in a small space. Their electrons are confined by having a tiny bit of conducting material surrounded on all sides by an insulating material. If the insulator is strong enough, and the conducting volume is small enough, then the confinement will force the electrons to have discrete (quantized) energy levels. These energy levels can influence the device behavior at a macroscopic scale, showing up, for example, as peaks in the conductance. Because of the quantized energy levels, quantum dots have been called "artificial atoms." Neighboring, weakly-coupled quantum dots have been called "artificial molecules." Not spelled out "quantum-dots."
423
424 quantum mechanics: theory which describes particles by a wavefunction
425 See
426
427 quantum Monte Carlo: a large class of computer algorithms that simulate quantum systems with the idea of solving the many-body problem. They use, in one way or another, the Monte Carlo method to handle the many-dimensional integrals that arise. Quantum Monte Carlo allows a direct representation of many-body effects in the wavefunction, at the cost of statistical uncertainty that can be reduced with more simulation time. For bosons, there exist numerically exact and polynomial-scaling algorithms. For fermions, there exist very good approximations and numerically exact exponentially scaling quantum Monte Carlo algorithms, but none that are both.
428 See
429
430 quantum optics: a field of research in physics, dealing with the application of quantum mechanics to phenomena involving light and its interactions with matter.
431 See
432
433 quantum theory: A theory of the interaction of matter and radiation developed early in the twentieth century which is based on the quantization of energy and applied to a wide variety of processes that involve an exchange of energy at the atomic level.
434 See
435
436 quantum transport
437
438 quantum well: Quantum well structures (QWs) consist of ultrathin layers of semiconductors having different composition and grown alternately one after another. Because of this structure, the position of the electronic energy levels is modulated in the direction normal to the layers.
439 See "Multiple quantum wells" in Applied Optics 26.2 (1987): 216.
440
441 quasibound: having closed boundaries at one side and open boundaries at the other
442 See
443
444 qubit: a quantum bit or unit of quantum information
445
446 Rappture: Rapid Application Infrastructure. Because the word is a portmanteau, only the initial letter should be capitalized.
447
448 resistivity: the ration of the applied voltage to the current
449
450
451 scanning probe microscopy: Scanning Probe Microscopy (SPM) is a branch of microscopy that forms images of surfaces using a physical probe that scans the specimen. An image of the surface is obtained by mechanically moving the probe in a raster scan of the specimen, line by line, and recording the probe-surface interaction as a function of position. SPM was founded with the invention of the scanning tunneling microscope in 1981.
452 See
453
454 Schottky barriers: a potential barrier formed at a metal-semiconductor junction which has rectifying characteristics, suitable for use as a diode. The largest differences between a Schottky barrier and a p-n junction are its typically lower junction voltage, and decreased (almost nonexistent) depletion width in the metal.
455 See
456
457 Schred: a tool that calculates the envelope wavefunctions and the corresponding bound-state energies in a typical MOS (Metal-Oxide-Semiconductor) or SOS (Semiconductor-Oxide-Semiconductor) structure and a typical SOI structure by solving self-consistently the one-dimensional (1-D) Poisson equation and the 1-D Schrödinger equation.
458 See . As in the case with Rappture, the word is a portmanteau; hence, only the initial letter should be capitalized.
459
460 Schrödinger's equation: In physics, especially quantum mechanics, the Schrödinger equation is an equation that describes how the quantum state of a physical system changes in time. It is as central to quantum mechanics as Newton's laws are to classical mechanics.
461 See
462
463 self-consistent
464
465 semiconductor: a material that has a resistivity value between that of a conductor and an insulator. The conductivity of a semiconductor material can be varied under an external electrical field. Devices made from semiconductor materials are the foundation of modern electronics, including radio, computers, telephones, and many other devices. Semiconductor devices include the transistor, many kinds of diodes including the light-emitting diode, the silicon controlled rectifier, and digital and analog integrated circuits. Solar photovoltaic panels are large semiconductor devices that directly convert light energy into electrical energy. In a metallic conductor, current is carried by the flow of electrons. In semiconductors, current can be carried either by the flow of electrons or by the flow of positively-charged "holes" in the electron structure of the material.
466 See
467
468 semi-empirical methods: Semi-empirical quantum chemistry methods are based on the Hartree-Fock formalism, but make many approximations and obtain some parameters from empirical data. They are very important in computational chemistry for treating large molecules where the full Hartree-Fock method without the approximations is too expensive. The use of empirical parameters appears to allow some inclusion of electron correlation effects into the methods.
469 Within the framework of Hartree-Fock calculations, some pieces of information (such as two-electron integrals) are sometimes approximated or completely omitted. In order to correct for this loss, semi-empirical methods are parametrized, that is their results are fitted by a set of parameters, normally in such a way as to produce results that best agree with experimental data, but sometimes to agree with ab initio results.
470 See
471
472 SOI: Silicon-on-insulator technology (SOI) refers to the use of a layered silicon-insulator-silicon substrate in place of conventional silicon substrates in semiconductor manufacturing, especially microelectronics, to reduce parasitic device capacitance and thereby improving performance.
473 See
474
475 In Schred, SOI means "semiconductor-oxide-insulator."
476
477
478 SOS: semiconductor-oxide-semiconductor (see about page for Schred).
479
480 SPICE: Simulation Program with Integrated Circuit Emphasis
481
482 In 1973, SPICE was introduced to the world by Professor Donald O. Pederson of the University of California at Berkeley, and a new era of computer-aided design (CAD) tools was born. As its name implies, SPICE is a "Simulation Program with Integrated Circuit Emphasis." You give it a description of an electrical circuit, made up of resistors, capacitors, inductors, and power sources, and SPICE will predict the performance of that circuit. Instead of bread-boarding new designs in the lab, circuit designers found they could optimize their designs on computers–in effect, using computers to build better computers. Since its introduction, SPICE has been commercialized and released in a dozen variants, such as H-SPICE, P-SPICE, and ADVICE.
483 See
484
485 SPICE3f4: developed at the University of California, Berkeley
486
487 spintronics: Spintronics (a neologism meaning "spin transport electronics"), also known as magnetoelectronics, is an emerging technology which exploits the intrinsic spin of electrons and its associated magnetic moment, in addition to its fundamental electronic charge, in solid-state devices.
488 See
489
490 state: a single solution to Schrödinger's equation defined by a unique set of quantum numbers
491 See
492
493 surface state: midgap state caused by the termination of the lattice at the surface of a semiconductor
494 See
495
496 TCAD: Technology Computer Aided Design
497
498 TEDVis: Theoretical Electron Density Visualizer
499
500 thermal transport: Thermal transport at sub-micron scales differs substantially from that at normal length scales. Physical laws for heat transfer, such as Fourier's law for heat conduction, fail when the mean free path of energy carriers becomes comparable to the length scales of interest. This occurs in modern microelectronic devices, where for example, channel dimensions, now below 100 nm in length, are comparable to the mean free path of phonons in silicon at room temperature. Research in the nanoscale thermal transport area addresses novel physics at small length and time scales and novel technologies that exploit this class of physics.
501 See
502
503 thermodynamics: In physics, thermodynamics (from the Greek θερμ-<θερμότης, therme, meaning "heat" and δυναμις, dynamis, meaning "power") is the study of the conversion of energy into work and heat and its relation to macroscopic variables such as temperature and pressure. Its underpinnings, based upon statistical predictions of the collective motion of particles from their microscopic behavior, is the field of statistical thermodynamics, a branch of statistical mechanics. Historically, thermodynamics developed out of need to increase the efficiency of early steam engines.
504 See
505
506 thyristors:
507
508 tight-binding: In solid-state physics, the tight-binding model is an approach to the calculation of electronic band structure using an approximate set of wavefunctions based upon superposition of wavefunctions for isolated atoms located at each atomic site. The method is closely related to the linear combination of atomic orbitals molecular orbital method used for molecules.
509 See
510
511 time-independent
512
513 transistor: contraction of transresistance, a term used to describe a resistance which is controlled by a voltage at another node
514 See
515
516 tunneling: quantum mechanical process by which a particle can pass through a barrier rather than having to go over a barrier
517 See
518
519 UTB: Ultra thin body/bodies
520
521 Vander Walls, van der Walls (tag also in Carbon nanotube based fixed-fixed NEMS): In physical chemistry, the van der Waals force (or van der Waals interaction), named after Dutch scientist Johannes Diderik van der Waals, is the attractive or repulsive force between molecules (or between parts of the same molecule) other than those due to covalent bonds or to the electrostatic interaction of ions with one another or with neutral molecules.
522 See
523
524 visualization: Simulators can produce all sorts of numbers, but the numbers themselves aren't terribly meaningful until they are put into context by visualization techniques. For example, the coordinates of the various atoms in a molecule don't readily convey the shape of the molecule. But once those coordinates are loaded into VMD, the the resulting picture conveys not only the shape of the molecule, but other important properties as well.
525 See
526
527 wavefunction: mathematical tool used in quantum mechanics to describe any physical system. See
528
529 workfunction:
530
531 well: doped region of opposite doping type used in a CMOS process
532 See
533
534 zeta function