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BEC Homepage Bose-Einstein Condensation in a gas: a new form of matter at the coldest temperatures in the universe... www.colorado.edu /physics/2000/bec   (17 words)

Bose-Einstein condensate - Wikipedia, the free encyclopedia However, superfluid helium-4 is not commonly referred to as a "Bose-Einstein condensate" because it is a liquid rather than a gas, which means that the interactions between the atoms are relatively strong. (The Einstein manuscript, believed to be lost, was found in a library at Leiden University in 2005.) The result of the efforts of Bose and Einstein is the concept of a Bose gas, governed by the Bose-Einstein statistics, which describes the statistical distribution of identical particles with integer spin, now known as bosons. "Bose-Einstein condensation in a gas of sodium atoms". en.wikipedia.org /wiki/Bose-Einstein_condensate   (1784 words)

BEC - What is it and where did the idea come from? Satyendra Nath Bose was studying the new idea (at that time) that the light came in little discrete packets (we now call these "quanta" or "photons"). Einstein liked them, and he was a very important scientist at that time, so he used his influence to get them published. Bose assumed certain rules for deciding when two photons should be counted up as either identical or different. www.colorado.edu /physics/2000/bec/what_is_it.html   (786 words)

Talk:Bose-Einstein condensate - Wikipedia, the free encyclopedia Bose condensation occurs when a macroscopic (from a thermodynamic point of view) number of particles are in the ground state. A superconductor can loosely be thought of as a bose condensed state of electrion pairs, but this is heuristic only. The easiest way to see this is that in bose condensation the ground state is at zero momentum. en.wikipedia.org /wiki/Talk:Bose-Einstein_condensate   (1728 words)

Article: Bose-Einstein Condensates, by Marissa K. Lingen Bose combined his work in thermodynamics and statistical mechanics with the quantum mechanical theories that were being developed, and Einstein carried the work to its natural conclusions and brought it to the public eye. The first condensate consisted of 2000 atoms; some condensates have been created that are the size of a dime (several million atoms), but still behave as one giant atom. A BEC beam would have greater precision and energy than a laser because even at their low kinetic energy state, the massive particles would be more energetic than the massless photons. www.strangehorizons.com /2001/20011210/bose-einstein.shtml   (2192 words)

Bose-Einstein condensate - Hutchinson encyclopedia article about Bose-Einstein condensate The first Bose-Einstein condensate was produced in June 1995 by US physicists cooling rubidium atoms to 10 billionths of a degree above absolute zero. Hypothesis put forward in 1924 by German-born US physicist Albert Einstein and Indian physicist Satyendra Bose, suggesting that when a dense gas is cooled to a little over absolute zero it will condense and its atoms will lose their individuality and act as an organized whole. A gaseous cloud of lithium atoms was cooled, with the use of laser beams, until weak chemical bonds between atoms produced paired sets of lithium atoms. encyclopedia.farlex.com /Bose-Einstein+condensate   (212 words)

Bose Einstein Condensate BEC setup, which on paper is no big deal any more, but.... In addition the collective variables connected to atomic groundstates in a BEC offer long coherence times at least on the order of tens of ms, so that one can imagine to write, store and retrieve nontrivial quantum correlations from light to atoms and back. We can have high optical density at a moderate number of atoms, so that technically it becomes feasable to detect effects due to the quantum fluctuations of the collective variables, which scale for atomic and light variables as the squareroot of the number of atoms and photons respectively. www.nbi.ku.dk /page39101.htm   (379 words)

AN EXCITING NEW STATE FOR EXCITONS By comparison, to create the first atomic Bose-Einstein condensates back in 1995, researchers at the University of Colorado had the daunting task of chilling a ball of rubidium atoms to as close to absolute zero as the laws of physics allow. Because the mass of these excitons was so much smaller than that of the atoms used to form atomic Bose-Einstein condensates, the critical temperature at which condensation occurred, about one degree Kelvin (-272 degrees Celsius or -459 degrees Fahrenheit) was much higher. "An exciton functions as a quasi-particle, akin to a hydrogen atom," says Butov, "which means that by reducing temperature or increasing density, it is a candidate to form a Bose-Einstein condensate." www.lbl.gov /Science-Articles/Archive/MSD-Bose-Einstein-Butov.html   (591 words)

The Science Show: 17 July  2004  - Bose-Einstein Condensate When we have a Bose-Einstein condensate we usually have about one hundred thousand or so atoms that are each described by exactly the same quantum mechanics so they behave identically and the particles are indistinguishable from each other, so it gives us a much larger and easier to probe system that’s very much quantum mechanical. In many ways the atoms in a Bose-Einstein condensate behaves similarly to light from a laser beam, so we could use that to make an interferometer in the same way that laser beams are used to make light interferometers and that has the potential to create some very sensitive measurement devices. Evaporative cooling techniques have made it possible for researchers using rubidium atoms to work at these seemingly impossible temperatures to study the movement of atoms in a Bose-Einstein condensate on an atom chip. www.abc.net.au /rn/science/ss/stories/s1127770.htm   (1161 words)

Bose-Einstein Condensates Named for the theorists Satyendra Nath Bose and Albert Einstein who predicted its existence, a Bose-Einstein condensate is an unusual state of matter that arises because of quantum mechanical effects on a collection of entities called bosons. A Bose-Einstein condensate needs to have a very low temperature to allow the bosons to "stick together" and the bosons must be microscopic so that quantum mechanical effects are important. Bose: "These three balls are bosons and they are part of a Bose-Einstein condensate. www.jupiterscientific.org /sciinfo/boseeinstein.html   (1178 words)

The Bose - Einstein Condensate This Bose-Einstein condensate (BEC), the first observed in a gas, can be thought of as the matter counterpart of the laser-except that in the condensate it is atoms, rather than photons, that dance in perfect unison. Einstein's theory requires that the atoms in a condensate have energy that is as low as possible, whereas Heisenberg's uncertainty principle forbids them from being at the very bottom of the trap. The condensate atoms have the smallest possible velocity and thus remain in a dense cluster in the centre of the cloud after it has expanded. www.fortunecity.com /emachines/e11/86/bose.html   (4187 words)

The Science Show: 2 March  2002  - Bose-Einstein Condensate And with the Bose-Einstein condensates we have this unique opportunity to do condensed matter physics at extremely low densities, at densities where the atoms are hundreds of nanometres away, so there's a lot of space between them. The Bose-Einstein condensates got a lot of press recently, it's a new form of matter which is for atoms what the laser is for light. In a Bose condensate all the atoms are just one giant matter wave, the atoms march in lock step, and this is very different from an ordinary gas where all the particles move around randomly. www.abc.net.au /rn/science/ss/stories/s494162.htm   (402 words)

Bose-Einstein Condensate in Hydrogen One common signature of a Bose-Einstein condensate is a sudden increase in density at the center of the cloud, as shown in this density plot for lithium atoms. Concluding a quest that lasted 20 years, a team of researchers has teased a sample of hydrogen gas into forming a Bose-Einstein condensate (BEC), a form of matter in which all of the atoms occupy the same quantum state. Atoms in the denser BEC have a slightly different spectrum of energy levels from those of the normal gas, so their fluorescence peaks at a different wavelength. focus.aps.org /story/v2/st22   (552 words)

ePrintsUQ - Homodyne Measurements on a Bose-Einstein Condensate We investigate a non-destructive measurement technique to monitor Josephson-like oscillations between two spatially separated neutral atom Bose-Einstein condensates. One condensate is placed in an optical cavity, which is strongly driven by a coherent optical field. The detected current is modulated by the coherent tunneling oscillations of the condensate. eprint.uq.edu.au /archive/00000259   (155 words)

Quantum Optics Innsbruck - Research Condensates were predicted to be possible by Einstein and Bose in 1924, and Bose-Einstein condensation has long been thought to be involved in superfluid liquid helium; but the textbook case of a gaseous condensate was not realized experimentally until 1995. A Bose-Einstein condensate is matter in a very unusual state, which is reached when certain gases are cooled to very low temperatures (millions of times colder than interstellar space), but kept at such low density (about a hundred-thousandth the density of air) that they cannot condense into ordinary liquids. Many atoms occupying the same quantum state means that a Bose-Einstein condensate is for particles of matter what a laser beam is for particles of light. th-physik.uibk.ac.at /qo/bec.html   (540 words)

Colder than a Wisconsin winter In fact, "Most of the questions we are currently answering with the Bose-Einstein condensate are to fill in the gaps between the 'ideal' non-interacting atom gas case Einstein considered (which is actually a bit boring), and the atoms in superfluid liquid helium," Wieman says. The picture is different for a group of atoms in a Bose-Einstein condensate. Although Einstein mentioned the Bose-Einstein state in passing, as a kind of curiosity, he thought the atoms would not interact once they'd reached it. whyfiles.org /052einstein/bose.html   (896 words)

Physics News Update In this process the condensate appears first to implode and then rebound somewhat like a supernova, even to the extent of sending out jets of particles and leaving behind a remnant. First, his group made a large (2 million atoms) BEC in the usual way (in a magnet trap), then loaded it into a magnetic trap by 40 cm, and finally loaded it into a microtrap on a printed circuit board. This, he said, might allow an atom-wave equivalent to the current process of down-conversion, by which UV photons can be converted, in a special crystal, into a pair of lower-energy but entangled photons (if one photon has a horizontal polarization, the other must have a vertical polarization; see Update 519). www.aip.org /enews/physnews/2002/split/581-1.html   (753 words)

einstein A BOSE EINSTEIN CONDENSATE (BEC) OF SODIUM ATOMS Bose Einstein condensates (BEC) provide a versatile testbed for looking at quantum phenomena. In 2002, BECs were formed from molecules of bosonic rubidium atoms newton.ex.ac.uk /aip/catagories/einstein.html   (213 words)

Research While it seems relatively certain that the basic mechanism is, as in the older ("BCS") superconductors, the formation of Cooper pairs (bound pairs of electrons which in some sense undergo Bose-Einstein condensation), both the nature of the pairs and the reasons for their formation are probably quite different from the traditional BCS picture. In 1995, BEC was achieved in a second atomic system, namely various atomic alkali gases confined in magnetic traps; in this case it can be observed very directly, through its spectacular effect on the density distribution. In addition,there is considerable interest in the effects of impurities, in the nature of the "pseudo- gap" (underdoped) regime and in alternative mechanisms of pair formation, in particular one based on enhanced screening of the fundamental Coulomb interaction. www.physics.uiuc.edu /research/CMTheory/research.htm   (1274 words)

The 2001 Nobel Prize in Physics - Information for the Public Repeated release from the trap of parts of a Bose-Einstein condensate of sodium atoms. Einstein rapidly extended the theory to cover Bose particles with mass and he himself published two articles in quick succession, predicting that when a given number of particles approach each other sufficiently closely and move sufficiently slowly they will together convert to the lowest energy state: what we now term Bose-Einstein condensation (BEC) occurs. Studies of phenomena related to BEC for fermions at extremely low temperatures by D. Jin and co-workers at JILA are revealing new aspects of the statistical conditions in physical systems, indicating future possibilities of observing atomic pair-formation and suprafluidity properties. nobelprize.org /physics/laureates/2001/public.html   (2522 words)

What is a Bose-Einstein condensate? They succeed in cooling about 2000 atoms of rubidium gas to 170 nanokelvin (170 billionths of a degree above absolute Kelvin), where they formed a Bose-Einstein condensate less than 100 micrometers across. Bose-Einstein condensation is a phenomenon that occurs at low temperatures in systems consisting of large numbers of bosons whose total number is conserved in collisions. The condensate lasted for about 15 seconds, and was cooled all the way down to 20 nanokelvin. www.physlink.com /Education/AskExperts/ae292.cfm   (179 words)

Igitur-archive These are nontrivial spin textures that in principlecan exist in a spinor Bose-Einstein condensate. In particular, we investigate the stability of skyrmions in a fictitious spin-1/2 condensate of 87-RB atoms. In addition to determining the size and the lifetime of the skyrmion, we also present its spin texture and finally briefly consider its dynamical properties. igitur-archive.library.uu.nl /phys/2001-1026-155124/UUindex.html   (183 words)

Researchers Develop All-Optical Bose-Einstein Condensate Georgia Institute of Technology physicists have demonstrated the first all-optical technique for producing Bose-Einstein condensates, a form of matter in which atoms cooled to a fraction of a degree above absolute zero stop their normal motion -- and enter a single quantum state in which all atoms behave identically. Chapman and his team began studying Bose-Einstein condensation because of their interest in controlling atoms for investigating quantum entanglements, which have applications for quantum logic -- a potential new area of computing. Chapman and his team have produced condensates containing up to 35,000 atoms, far less than the millions of atoms captured by magnetic means. gtresearchnews.gatech.edu /newsrelease/BOSE.html   (1034 words)

Bose-Einstein Condensate: A New Form of Matter The atoms within the condensate obey the laws of quantum physics and are as close to absolute zero—minus 273.15 Celsius or minus 459.67 degrees Fahrenheit—as the laws of physics will allow. Cornell came up with an improvement to the standard magnetic trap—called a time-averaged orbiting potential trap—that was the final breakthrough which allowed them to form the condensate. BEC pioneers Cornell and Wieman are continuing to explore the properties of their discovery. www.nist.gov /public_affairs/releases/BEC_background.htm   (1243 words)

Bose-Einstein Condensate First off, we learn that the Bose-Einstein condensate is a new state of matter (a fifth state, the other four being gas, liquid, solid and plasma). This year the Nobel Prize in Physics went to two scientists, Eric Cornell of the National Institute of Standards and Technology and Carl Wieman at Colorado University, who were the first to achieve a Bose-Einstein (BEC) condensate in neutral atoms (The 2001 Nobel Prize in Physics and BECs win prizes). It was predicted in 1924 by A. Einstein and S. Bose but not created until 1995. www.suite101.com /article.cfm/science_surfing/87377   (445 words)

Physicists Slow Speed of Light This so-called Bose-Einstein condensate was not actually made until 1995, because the right technological pot to cook it up in did not exist. Einstein's theory of relativity places an upper, but not lower, limit on the speed of light. Vacuums hundreds of trillions of times lower than the pressure of air at Earth's surface, and temperatures almost a billion times colder that that in interstellar space, are needed to produce the condensate. www.news.harvard.edu /gazette/1999/02.18/light.html   (1133 words)

Physics Today Online - Search & Discovery He, it is rather difficult to study properties of the condensate, such as the condensate fraction, whereas the measurement of superfluidity is fairly straightforward. The cores of the BEC vortices are relatively large compared to the size of the trapped condensate, and so only a small number of vortices can be cleanly observed. By rotating the toggling about the long axis of the trap, the researchers rotate the asymmetric potential, which stirs the condensate. www.aip.org /pt/vol-53/iss-8/p19.html   (1421 words)

Bose-Einstein condensate Since the first observation in 1995 of Bose-Einstein condensation (BEC) in a dilute atomic gas, the physics of this new matter state has been intensively investigated by about thirty groups in the world. The temperature of the condensate is not measurable but is 700 nK at the phase transition. In the intermediate situation, the position distribution after time-of-flight is bimodal: the narrow peak of the condensed part is superimposed with a broad gaussian for the non-condensed part. www-lplgb.univ-paris13.fr /Gb/Equipes/GroupeCOMETA/GroupeCOMETA.htm   (2591 words)

Bose-Einstein condensate Bose-Einstein Condensate Turns 10: Creation in Colorado Laboratory Gave Birth to New Field, Discoveries. Quantum unity stands.(Bose Einstein condensate is manipulated in experiment)(Brief Article) (the potential for an atomic laser based on the Bose-Einstein condensate is discussed at an American Physical Society meeting in Ann Arbor, MI)(Brief Article) www.infoplease.com /ce6/sci/A0808416.html   (193 words)

Alternate View Column AV-77 In fact, the more atoms that have been stored in the BEC, the stronger is the tendency for more atoms to join them, and the strength of this "pull" increases as the factorial of the number of atoms in the condensate. The size of a BEC of any number of atoms is the same as the size of one atom in the same state. To produce a BEC, a gas of weakly interacting bosonic molecules must be cooled to an ultra-low temperature at which the deBroglie wavelength of the molecules becomes larger than their mean spacing. www.npl.washington.edu /AV/altvw77.html   (2186 words)

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