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Search Result for: electrons Technology and Health News
The new devices can operate at 30 degrees above zero, rather than less than 70. This is the characteristic of the new generation of semiconductors, researched at the Italian Institute for the Physics of Matter (INFM-CNR), and in the Ludwig Maximilian University in Monaco of Bavaria and the ETH Zurich (the study).
Today there are two ways to record information on a medium: the electronic format, in which the binary language is the passage of electrons (the transistors) and magnetic (MRAM memory), more recently, in which the binary language is given by state of magnetization. To communicate these two systems could boost significantly the computational schemes, pending the distant quantum computer. Doubling the processing power and memory of a chip while maintaining the size, without the need to go in nano-scale (a scale, that is, a billionth of a meter) are just two of the technology that promises magnetic semiconductors suggest a near future.
These devices were made over ten years ago, but so far required temperatures far below zero to work. The problem now seems outdated as the known semiconductors gallium arsenide containing traces of manganese, a metal which has ferromagnetic properties at around 200 degrees below zero. To increase the temperature threshold, above which the ferromagnetic behavior disappears, the researchers deposited on a semiconductor film of iron - metal known for its magnetic properties - the thickness of a few nanometers.
Iron and manganese interacted so effectively that the new material, has a ferromagnetic behavior up to 30 degrees above zero, a jump of over a hundred degrees above the starting temperature.
This result is a technological response parallel to that of the race to miniaturization and the research was selected the American Physical Society as one of the most important published in Physical Review Letters
The switch that turns off and on to command the superconducting property of the new device is a trivial electric field. In practice, what has been done by Andrea Ankle and colleagues at the University of Geneva in the first superconducting transistors. The operation, represents a milestone of applied physics and paves the way for the development of a new generation of microchips - and therefore computers - much faster than at present.
To understand how and why the device is considered so promising it must be from another discovery, made last year by the same group of university research in Switzerland and published in Science. In one study, physicists have created a single crystal in which two metal oxides (strontium titanate and lanthanum aluminate) are separated. Between these two materials, researchers have found a layer of free electrons (electronic cloud) and 0.3 Kelvin - that is just above absolute zero - traveling without any resistance. At that temperature, the crystal becomes a superconductor.
Scientists have now discovered how to turn off and turn on the superconductivity of this crystal at will, or modules, simply by applying an electric field to the point of contact between the two oxides. The result is a version of superconductive field effect transistors (FET) devices known in applied physics, able to switch from one state to a semiconductor insulator, and basic digital information in electronics (the fact that the current can pass or not is used as a binary 1-0 to store information).
As the field effect transistors is a semiconductor, however, it always has resistance to the passage of current. This means that the speed at which you can get the electrons when the device is "on" is limited which means heat develops beyond a certain limit. This side effect is damaging the transistor.
A superconducting transistor, however, can pass electrons (and record information) much more quickly, as it does not oppose any resistance to the passage of current and, therefore, not heat. There remains the problem of extremely low temperatures required for superconductivity. A limit that research is a long time trying to overcome.
A new advanced thermometer, based on noise Johnson, increased by five times the accuracy of current systems
After seven years of work, researchers from the National Institute of Standards and Technology (Nist), the U.S. organization for the development of technologies, have managed to build a new type of thermometer, Johnson Noise Thermometer (Jnt), defined by the same scientists a goal of thermometry, which advances to five times the current state of the art. The new device will in fact take measurements of extreme precision, never obtained so far, fundamental for basic research and for the definition of units of measurement. At the head of the project is Sam Benz, the Quantum Devices Group, which officially presented it on June 9th at a conference on measures of accuracy in Broomfield, Colorado.
The new thermometer provides the temperature starting from noise Johnson (hence the name), generated by the random motion of electrons inside a resistance. This measure is directly proportional to the temperature, and the system makes it possible to reduce the error without any additional calibrations. "All measurements are electrical, and do not require volumes of gas or mechanical systems that sometimes, depending on environmental conditions, could give approximate results." says Benz, " beauty is that the measurement is also very simple to perform. "
Particles in a confined microscopic space, move in a coordinated manner and can be manipulated and observed with a precision never achieved.
A nano-trap can be imagined as a tube the size of a billionth of a meter in which electrons are closed to study their behavior. Thus, scientists from the centers of the Italian Institute for physics of matter of Cnr "S3", Modena and "Nest" of Pisa in collaboration with Columbia University in New York, were able to observe with great precision the behavior of a quartet of electrons confined in one of these structures. Result: the particles move in a coordinated manner and with precise frequencies and can be manipulated. The study was published in Nature Phisics.
As it is known, the physics of the matter the size of an atom or less follows different laws than those of classical physics. According to these principles, which fall in quantum physics, the behavior of particles such as electrons can not be described as we are used to (for larger bjects),but it is outlined mainly in terms of probabilistic forecasts.
The technique developed by Cnr made it possible to determine the frequency of vibrations of particles through the use of a beam of laser light. The electrons in a nano-trap can only move in a coordinated manner and in accordance with the laws of quantum mechanics, vibrate at frequencies well defined that, thanks to this method, was possible to measure with unprecedented precision.
For the first time there was a negative charge exactly equal to 25 percent of that unit. Research in Nature magazine.
Since the electricity comes from the transport of electrons, it is logical to expect that the smallest load that can be transported is equal to the charge of a single electron. Under specific conditions, it is possible to observe portions of this fundamental unit. Even in these conditions, however, there have been observed only odd fractions of charge: third, fifth, seventh. In the last issue of Nature it was published the existence of a quasi-particle with a charge corresponding exactly a quarter of that of an electron.
In particular, these unique elementary particles, which have been precisely called "quasi-particles" to their particular nature, are formed when electrons are confined in a two-dimensional system, which forces them to interact strongly with each other. It is known that when a flow of electrons is confined in a two-dimensional plan of a semiconductor and it is applied simultaneously in a strong magnetic field perpendicular to this plane, the electrons have unusual quantum properties. In a research just published in Nature, in an electron gas, two-dimensional and ultra-pure, were detected within the fluid vortexes charges carrying exactly one quarter of the charge of an electron.
How can you convert waste into energy in the most efficient way possible? The secret is in riboflavin.
The microorganisms have the ability to change the chemistry of the environment. This is known for a long time, but if some of these can generate energy from the degradation of organic compounds has not yet been clarified. One answer comes from an American study published in Proceedings of the National Academy of Sciences (Pnas): BioTechnology researchers from the Institute of the University of Minnesota have found that the riboflavin, better known as vitamin B-2, is the key to the production of electricity by the microorganism Shewanella, a bacterium that is commonly found in water and soil.
Filming particles is now possible. It was done for the first time by a group of Swedish researchers using extremely short pulses of light
Getting images of electrons that do not appear to "move" has been impossible because of the speed of these microscopic particles. But a group of researchers in the Faculty of Engineering at the University of Lund (Sweden) now has found a way to shoot the movement of an electron using an innovative technique that provides for the use of flash light of extremely short duration.
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