Started by Recusant, October 13, 2022, 10:26:27 PM
QuoteIt was one of those happy accidents of science. Northeastern professor Randall Erb and Ph.D. student Jason Bice were working on a product for a university client—and wound up with an entirely new class of material.Their discovery of an all-ceramic that can be compression-molded into complex parts—an industry breakthrough—could transform the design and construction of heat-emitting electronics, including cellphones and other radio components."Our research group's lives are very much situated at the bleeding edge of technology," says Erb, an associate professor of mechanical and industrial engineering who heads the DAPS Lab at Northeastern. "Things break a lot, and every once in a while one of those breaks turns out to be good fortune."Last July, Erb was in his Northeastern lab with Bice, who has since earned a mechanical engineering Ph.D. They were testing an experimental ceramic compound as part of a hypersonic project for an industrial partner when something appeared to go wrong."We blasted it with a blowtorch and, while we were loading it, it unexpectedly deformed and fell out of the fixture," Erb says. "We looked at the sample on the floor thinking that it was a failure."Closer examination gave way to a revelation."We realized it was perfectly intact," Erb says. "It was just shaped differently."[Continues . . .]
QuoteScientists are always looking for the next weird and wonderful material, and they've just found it: A bosonic correlated insulator to give it its technical name, which is both a new material and, indeed, a whole new state of matter.It's a lattice formed from a layer of tungsten diselenide and a layer of tungsten disulfide placed on top of each other but not fully aligned.That slight misalignment creates what's known as a moiré pattern, and here has revealed some interesting properties.To understand what's special about the material, you need to understand what bosons and fermions are. At the quantum level, particles are grouped into two main types: bosons (force carriers like photons) that can share the same quantum state, and fermions (matter particles like electrons), which can't. Usually, fermions are easier to work with."Conventionally, people have spent most of their efforts to understand what happens when you put many fermions together," says condensed matter physicist Chenhao Jin from the University of California, Santa Barbara (UCSB)."The main thrust of our work is that we basically made a new material out of interacting bosons."[Continues . . .]
QuoteAbstract:A panoply of unconventional electronic states has been observed in moiré superlattices. Engineering similar bosonic phases remains, however, largely unexplored. We report the observation of a bosonic correlated insulator in tungsten diselenide/tungsten disulfide (WSe2/WS2) moiré superlattices composed of excitons, that is, tightly bound electron-hole pairs. We develop a pump probe spectroscopy method that we use to observe an exciton incompressible state at exciton filling νex = 1 and charge neutrality, indicating a correlated insulator of excitons. With varying charge density, the bosonic correlated insulator continuously transitions into an electron correlated insulator at charge filling νe = 1, suggesting a mixed correlated insulating state between the two limits. Our studies establish semiconducting moiré superlattices as an intriguing platform for engineering bosonic phases.
Quote from: Tank on June 20, 2023, 08:48:41 PMMy mind is officially blown!
Quote from: hermes2015 on October 14, 2022, 04:08:24 AMThanks for that interesting link. So many important discoveries are the result of happy accidents. First class scientists are open minded and alert, so they notice interesting results in "failed" experiments. The accidental discovery of mauveine by Perkin when he was in his tens is a classic example.https://www.vox.com/science-and-health/2018/3/12/17109258/sir-william-henry-perkin-google-doodle-birthday-180-mauveine-purple-dye
Quote from: Icarus on July 28, 2023, 12:07:36 AMHere is another important development aimed at heat mitigation.