![]() ![]() 229), one of the first theorists to propose supersolidity, doubts that Chan and Kim have uncovered the supersolidity that he and other theorists have envisioned. Leggett of the University of Illinois at Urbana-Champaign (SN: 10/11/03, p. In supersolid helium, the particles rotating the Bose-Einstein condensate are probably not the helium atoms but the lattice vacancies, he says.Īnthony J. Vacancies in a crystal can behave like particles, Halperin explains. Now, helium-4 has become the first solid Bose-Einstein condensate, according to the new experiment. Decades earlier, isotopes of helium were discovered to form liquid Bose-Einstein condensates. Since 1995, physicists have made numerous gaseous Bose-Einstein condensates from atoms of certain metals and from some simple molecules (SN: 11/22/03, p. In such a condensate, atomic or subatomic particles share the same quantum state, amassing into what is, in essence, a single superparticle. Solid helium's superfluidity indicates that a so-called Bose-Einstein condensate forms within the material. For the solid to act this way, atoms and vacancies within its crystal lattice may be continuously exchanging places. but all the data indicate that, indeed, this helium did become unstuck," Chan says. "Ordinarily, you would not imagine that this solid could become unstuck. Then they infiltrated the disk's pores with liquid helium and froze the helium under pressure at temperatures near absolute zero.Īs the scientists continued to lower the temperature, they detected signs that at about 175 millikelvins the solid version of the isotope helium-4 stopped being dragged around because of friction with the disk. To explore the behavior of solid helium, the researchers placed inside the oscillator's bob a porous glass disk the diameter of a dime. Basically, it's a squat, cylindrical bob suspended from a hollow copper tube that slowly gyrates back and forth. Building on a previous approach, Chan and Kim entered the fray with a device called a torsional oscillator. Halperin of Northwestern University in Evanston, Ill., calls the new evidence for supersolidity a "sensational result."įor more than 30 years, theorists have predicted supersolidity, but experimentalists had been unable to demonstrate it. Beamish of the University of Alberta in Edmonton in a commentary accompanying the report. "If this discovery of a supersolid is confirmed, it is a major advance," says John R. 15 Nature, he and his Penn State colleague Eun-Seong Kim present evidence for what they suspect is the world's first supersolid. "Now, we're saying that even in a solid we can see it," Chan says. Chan of Pennsylvania State University in State College.įrictionless flow, also known as superfluidity, has previously been observed only in liquids and gases (SN: 10/25/03, p. In that extraordinary state, known as a superfluid solid or supersolid, the material is expected to flow like a liquid yet maintain its solid crystal structure, says team leader Moses H.W. Retrieved from Ĭaptured within the cavities of a porous glass disk, frozen helium has coalesced into a long-awaited, but never-before-observed, quantum phase of matter, a team of physicists claims. APA style: A solid like no other: frigid, solid helium streams like a liquid.A solid like no other: frigid, solid helium streams like a liquid." Retrieved from #Solid helium free#MLA style: "A solid like no other: frigid, solid helium streams like a liquid." The Free Library. ![]()
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