what are quantum dots?
367552
Quantum dots are small devices that contain a tiny droplet of free electrons. They are fabricated in semiconductor materials and have typical dimensions between nanometres to a few microns
831388
Light Emitting Diodes and How They Work.\n\nhttp://electronics.howstuffworks.com/led.htm
779218
Here's a great and simple explaination from Wikiopedia: \n\nIn atomic physics and quantum chemistry, the electron configuration is the arrangement of electrons in an atom, molecule, or other physical structure (eg, a crystal).\n\nLike other elementary particles, the electron is subject to the laws of quantum mechanics, and exhibits both particle-like and wave-like properties. Formally, the quantum state of a particular electron is defined by its wavefunction, a complex-valued function of space and time. According to the Copenhagen interpretation of quantum mechanics, a particular electron is both "nowhere at all" and "everywhere all at once" until an act of measurement causes it to be detected. The probability that the act of measurement will detect the electron at a particular point in space is proportional to the square of the absolute value of the wavefunction at that point.\n\nElectrons are able to jump from one energy level to another by emission or absorption of a quantum of energy, in the form of a photon. Because of the Pauli exclusion principle, no more than two electrons may exist in a given atomic orbital; therefore an electron may only leap to another orbital if there is a vacancy there.\n\nKnowledge of the electron configuration of different atoms helps us understand the structure of the periodic table of elements. The concept is also useful for describing the chemical bonds that hold molecules together. And in a macro sense this same idea helps explain the peculiar properties of lasers and semiconductors\n\n\nThe other links are also good sources for review and expaination\n\nGood luck
188537
Tunneling Theory \n  \nThe simplest model of quantum transport in devices is to describe the problem in terms of the scattering of the electron wavefunction by a spatially varying potential. One assumes that this potential is situated between two electron reservoirs, each of which emits particles with an equilibrium distribution into the scattering region. The reservoirs will, in general, have different chemical potentials, their difference representing an applied bias voltage. The net flux of electrons passing between the reservoirs constitutes the electrical current conducted by the device. A single-particle Schrödinger equation can only describe a situation in which the electrons move perfectly coherently throughout the device. Any loss of coherence due to inelastic collisions requires a higher-level description. Nevertheless, the solutions of Schrödinger 's equation remain one of the fundamental tools available to understand and predict the behavior of quantum-scale devices.
48832
Nano means "dwarf" in Greek and deals with technology (nanotech) on the truly small acale, like one billionth.\n\nNanotechnology tries to find new uses for material that is often highly pure and put together at the electron-microscopic scale.\n\nFor examply carbon Buckyballs are molecules that consist of 60 carbon atoms arranged by vapor deposition into what looks like tiny soccer balls.  It may be possible for these to hold and release medications, etc.\n\nSome say that when putting atoms together using nanotech, it is like adding new elements to the periodic table, thus predicting how they will react with other materials.\n\nMother Nature has always used her own nanotech to put together amazing substances (consider the diamond formed perhaps sixty miles down in a volcanic lab!).  Now we hope to do amazing things too in our much "coooler" labs.  Albany, NY is fast becoming a new center for the study and application of nanotechnology.  One company (Daystar) plans to start manufacturing cheaper film photovoltaic cells that could provide all the power we need if we shingled all our buildings with them.
559402
Metal Oxide Semiconductor Field Effect Transistor.  It's the basic component of most electronic circuits and all digital ones.  It's the breakthrough that made computers so cheap, small and popular.  A transistor, you know, acts as an electrical "gate," acting on a smaller input voltage to allow a larger voltage to pass through.  So a transistor can act as an amplifier, by using a smaller current to control a larger current.  Used in a circuit called a "flip-flop," it makes up the basic circuit for computers and other digital electronics.\n\nThere are many kinds of transistors, dating all the way back to vacuum tubes; the reason MOSFETs are such a big deal is because they are made by "printing," in huge quantities and on extremely small scales, directly onto microchips.
863976
nanotechnology is engineering that deals with the study of molecular and atomic particles, measured in nanometers (billionths of a meter or 10 to the-9 ).
396728
The major application of quantum dots is labeling (if used alone) or barcoding (when used in combination). They are great as fluorescent/luminescent/etc. labels.\n\nFor brief list of applications, read:\nhttp://www.evidenttech.com/applications/quantum-dot-biotech-applications.php\n\nFor barcoding, see:\nhttp://www.newscientist.com/article.ns?id=dn953
80881
A quantum computer is any device for computation that makes direct use of distinctively quantum mechanical phenomena, such as superposition and entanglement, to perform operations on data. In a classical (or conventional) computer, the amount of data is measured by bits; in a quantum computer, it is measured by qubits. The basic principle of quantum computation is that the quantum properties of particles can be used to represent and structure data, and that devised quantum mechanisms can be used to perform operations with this data. For a generally accessible overview of quantum computing, see Quantum Computing with Molecules, an article in Scientific American by Neil Gershenfeld and Isaac L. Chuang.\n\nhttp://www.answers.com/topic/quantum-computer?method=22
990811
Quantum mechanics is a fundamental physical theory which extends and corrects Newtonian mechanics, especially at the atomic and subatomic levels. It is the underlying framework of many fields of physics and chemistry, including condensed matter physics, quantum chemistry, and particle physics. The term quantum (Latin, "how much") refers to the discrete units that the theory assigns to certain physical quantities, such as the energy of an atom at rest.
937754
Something involving atomic spectra.  For example see\nhttp://www.fas.harvard.edu/~scdiroff/lds/QuantumRelativity/StreetLampSpectra/StreetLampSpectra.html
1144534
There are still issues on nanomanufacturing.  If you want to know, nano-electronics are made from nanotransistors.  These nanotransistors are made from carbon nanotubes - they look like sot after a chimney sweep.\n\nThere are already companies involved in nanotechnology.  A few of them are in Massachusetts.  I believe the new generation of optical electronics will have nanotechnology - probably around 2008.
49809
nanotechnology\nThe science of developing materials at the atomic and molecular level in order to imbue them with special electrical and chemical properties. Nanotechnology, which deals with devices typically less than 100 nanometers in size, is expected to make a significant contribution to the fields of computer storage, semiconductors, biotechnology, manufacturing and energy.\n\nEnvisioned are all kinds of amazing products, including extraordinarily tiny computers that are very powerful, building materials that withstand earthquakes, advanced systems for drug delivery and custom-tailored pharmaceuticals as well as the elimination of invasive surgery, because repairs can be made from within the body.\n\nLarry Bock, CEO of Nanosys, who helped launch more than a dozen successful biotech companies in his career, believes that nanotech will impact even more industries than biotech. In an excerpted article from the March 2003 Nanotech Report, he compared nanotechnology with the microelectronics industry. Bock said that "a single chemistry graduate student can create novel devices and device architectures not even imaginable or manufacturable by today's biggest microprocessor companies. That is because these devices are fabricated chemically, or from the bottom up. Existing microelectronics technology is fabricated by etching wafers, or from the top down." See AFM, STM, Buckyball, nanotube and MEMS.
353389
Nanotechnology.  Creating or manufacturing very, very. very tiny parts and machinery
337149
Quantum corrals are two dimensional structures built atom by atom on an atomically clean metallic surface using a scanning tunneling microscope. These two dimensional structures ``corral'' electrons in the surface states of noble metals which lead to standing wave patterns in the electron density inside the quantum corral. We review the physics of quantum corrals and relate the signal of the scanning tunneling microscope to the scattering properties of substrate electrons from atomic impurities supported on the surface. The theory includes the effects of incoherent surface state electron scattering at the impurities and quantitively describes all of the current STM data on quantum corrals, including the recent quantum mirage experiments with Kondo effect. We discuss the physics underlying the recent mirage experiments and review some of the outstanding questions regarding Kondo effect from impurities in nanoscale structures on metallic surfaces. We also summarize recent work on variations of ``quantum'' corrals: optical corrals and acoustical corrals
708599
http://www.science.uwaterloo.ca/~cchieh/cact/c120/dotstruc.html
1125293
Nanotechnology has yielded a number of unique structures that are not found anywhere in nature.  Most demonstrate an essential quality of quantum mechanics known as quantum confinement.  The idea behind confinement is all about keeping electrons trapped in a small area.  The sizes we're talking about here for confinement have to be less than 30 nm for effective confinement.  Quantum confinement comes in several flavors.  2-D confinement is only restricted in one dimension, and the result is a quantum well (or plane).  These are what most lasers are currently built from.  1-D confinement occurs in nanowires.  0-D confinement is found only in the quantum dot.\n\nYou're probably wondering why confinement is so important.  For one thing, it leads to new electronic properties that are not present in today's semiconductor devices.  Consider the quantum dot.  The typical quantum dot is anywhere between 3-60 nm in diameter.  That's still 30 to 600 times the size of a typical atom.  A quantum dot exhibits 0-D confinement, meaning that electrons are confined in all three dimensions.  The only things in nature that have 0-D confinement are atoms.  So a quantum dot can be loosely described as an 'artificial atom'.  This is vitally important because we can't readily experiment on regular atoms.  They're too small and too difficult to isolate in an experiment.  Quantum dots, on the other hand, are large enough to be manipulated by magnetic fields and can even be moved around with an STM or AFM.  We can deduce many important atomistic characteristics from a quantum dot that would otherwise be impossible to research in an atom.\n\nConfinement also increases the efficiency of today's electronics.  The laser is based on a 2-D confinement layer that is usually created with some form of epitaxy like Molecular Beam Epitaxy or Chemical Vapor Deposition.  The bulk of modern lasers created with this method are highly functional, but ultimately inefficient in terms of energy consumption and heat dissipation.  Moving to 1-D confinement in wires or 0-D confinement in quantum dots allows for higher efficiencies and brighter lasers.  Quantum dot lasers are currently the best lasers available though their fabrication is still being worked out.\n\nAll of these solid nanostructures are very important to nanotechnology research.  There are several other structures that are also academically interesting.  Nanotubes and Buckyballs are a class of materials that are hollow.  They are all based on carbon forms that are wrapped to form a shell.  The carbon nanotube, for instance, has drawn much attention as one of the principal nanostructures that exhibit some great potential in nano-electro-mechanical-systems (NEMS).  \n\nIn the following sections we shall discuss the many structures currently under investigation by researchers around the world.  After we've finished discussing these structures, we will move on to their numerous applications in industry and consumer goods.