Tuesday, December 8, 2009

Laser-Induced Magnetism synthetic


For the first time, physicists have been able to create "synthetic magnetism. This rare condition, which is reached by using laser light, causes the atoms to behave exactly as if they are charged particles within a magnetic field, even though they have no charge and there is no field these characteristics. Far from being a laboratory curiosity, this experiment will provide new ways of studying the nature of some particular states of matter.
There are a number of phenomena, almost always related to the world of subatomic particles and quantum physics that are of interest to physicists. The way they interact with two electrons in two dimensions contained within a magnetic field, for example, is difficult to investigate using conventional materials such as semiconductors. Not only is it difficult to control the many variables involved, but the samples used are defects or irregularities have little help in reaching a reliable result. However, this type of research is important. Not only for basic physics, but for the development of new devices useful for quantum computing and information science. The "synthetic magnetism, induced by the use of laser light, gives scientists a new way of modeling and analyzing quantum systems while maintaining full control of all parameters involved.

"The creation of synthetic magnetic fields for neutral atoms to design experiments that were impossible until now," says Ian Spielman, leader of the research group of the Joint Quantum Institute and the National Fitness Institute of Standards and Technology (NIST). Spielman is the specialist who wrote the article on this subject which is published in the latest issue of the journal Nature. The scientists used in their experiment a group of atoms of rubidium-87, which were "slowed" by the Zeeman method and then lock them in a magneto-optical trap. These atoms were subjected to further evaporative cooling until a temperature just above absolute zero (only 100 nano-Kelvin). Under conditions of low energy, the atoms form that physicists call a "Bose-Einstein condensate (BEC). This is a very strange state of matter in which most of the atoms of a group occupy the same quantum state of energy, behaving as if they were a single "super atom."

"The atoms form a "Bose-Einstein condensate"


Then, we applied a small (and variable) magnetic field perpendicular to the BEC, producing a gradient which atoms affected differently depending on their position along an axis of the magneto-optical trap. Then, two lasers with a wavelength of 801.7 nm (near infrared), oriented at angles of 90 degrees from each other, focused on atoms. As a result of the interaction between the magnetic field and laser beams, it altered the properties of atoms in different ways, depending on their location within the trap. As a result of all this nonsense that only physicists enjoy the atoms located at specific points began to move in a way that Spielman had been predicted earlier this year as you would a charged particle rotating in a magnetic field .

This experiment, says Spielman, "will have a substantial impact on various areas of quantum research, particularly as regards the behavior of electrons confined in different geometries, as in real materials." Who knows, maybe your next computer or sex toy to work through the principles discovered by Spielman.

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