Insulators
Researchers discover true 3D topological insulator
February 5, 2013 11:33 am | News | Comments
The material Samarium hexaboride (SmB6) has been around since the late 1960s—but understanding its low temperature behavior has remained a mystery until recently. Experts at three different research institutions have recently confirmed that this material is the first true 3D topological insulator, confirming a 2010 prediction by Joint Quantum Institute/CMTC theorists.
Researchers construct invisibility cloak for thermal flow
May 9, 2013 11:16 am | News | Comments
By means of special metamaterials, light and sound can be passed around objects....
Report: First discovery of a natural topological insulator
March 6, 2013 10:59 am | News | Comments
Unlike conventional electrical insulators, which do not conduct electricity, topological...
With voltage, “smart” oxide flips from open to closed
February 8, 2013 11:48 am | News | Comments
Researchers have tried for decades to replicate the effects of transistors in transition metal...
Honeycomb nets from bismuth cubes
March 19, 2013 8:07 am | News | CommentsResearchers from Dresden have discovered a new material that conducts electric currents without loss of power over its edges and remains an insulator in its interior. The material is made out of bismuth cubes packed in a honeycomb motif that is known from the graphene structure. As opposed to graphene, the new material exhibits its peculiar electrical property at room temperature, giving it promise for applications in nanoelectronics.
Surprising control over photoelectrons from a topological insulator
March 13, 2013 10:17 am | News | CommentsElectrons flowing swiftly across the surface of topological insulators are "spin polarized," their spin and momentum locked. This new way to control electron distribution in spintronic devices makes TIs a hot topic in materials science. Now scientists have discovered more surprises: contrary to assumptions, the spin polarization of photoemitted electrons from a topological insulator is wholly determined in three dimensions by the polarization of the incident light beam.
Engineers show feasibility of superfast materials
February 13, 2013 1:44 pm | News | CommentsUniversity of Utah engineers demonstrated it is feasible to build the first organic materials that conduct electricity on their edges, but act as an insulator inside. These materials, called organic topological insulators, could shuttle information at the speed of light in quantum computers and other high-speed electronic devices.
Technique points toward 2D devices
January 28, 2013 7:59 am | News | CommentsRice University scientists have taken an important step toward the creation of 2D electronics with a process to make patterns in atom-thick layers that combine a conductor and an insulator. The materials at play—graphene and hexagonal boron nitride—have been merged into sheets and built into a variety of patterns at nanoscale dimensions.
Physicists take photonic topological insulators to the next level
December 26, 2012 8:13 am | News | CommentsResearchers at The University of Texas at Austin have designed a simulation that, for the first time, emulates key properties of electronic topological insulators. Their simulation is part of a rapidly moving scientific race to understand and exploit the potential of topological insulators, which are a state of matter that was only discovered in the past decade.
Recipe for oxide interface perfection opens path to novel materials
November 16, 2012 3:22 pm | News | CommentsBy tweaking the formula for growing oxide thin films, researchers at Oak Ridge National Laboratory achieved virtual perfection at the interface of two insulator materials. The research team demonstrated that a single unit cell layer of lanthanum aluminate grown on a strontium titanate substrate is sufficient to stabilize a chemically and atomically sharp interface.
Physicists bring fresh insights into topological insulators
October 26, 2012 11:28 am | News | CommentsThe latest research by Boston College physicists offers fresh insights into topological insulators, a class of materials with unique properties that challenge some of the oldest laws of physics. The physicists report that the placement of tiny ripples on the surface of a topological insulator engineered from bismuth telluride effectively modulates so-called Dirac electrons so they flow in a pathway that mirrors the topography of the crystal's surface.
Droplet response to electric voltage in solids exposed
October 23, 2012 4:09 pm | News | CommentsFor the first time, scientists have observed how droplets within solids deform and burst under high electric voltages. This is important, according to the Duke University engineers who made the observation, because it explains a major reason why such materials as insulation for electrical power lines eventually fail and cause blackouts.
Electrons caught in the act
September 18, 2012 3:34 am | by David L. Chandler, MIT News Office | News | CommentsTopological insulators are exotic materials, discovered just a few years ago, that hold great promise for new kinds of electronic devices. The unusual behavior of electrons within them has been very difficult to study, but new techniques developed by a team of researchers could help unlock the mysteries of exactly how electrons move and react in these materials, opening up new possibilities for harnessing them.
Magnetic insulator shows way to dissipationless electronics
August 20, 2012 8:01 am | News | CommentsA team of researchers at in Japan has demonstrated a new material that promises to eliminate loss in electrical power transmission. Their methodology for solving this classic energy problem is based on a highly exotic type of magnetic semiconductor first theorized less than a decade ago—a magnetic topological insulator.
Hydrogen flips switch on vanadium oxide
May 21, 2012 5:17 am | News | CommentsIf you are not a condensed matter physicist, vanadium oxide may be the coolest material you've never heard of. It's a metal. It's an insulator. It's a window coating and an optical switch. And thanks to a new study by physicists at Rice University, scientists have a new way to reversibly alter vanadium oxide's electronic properties by treating it with one of the simplest substances—hydrogen.
A new world of spintronics with topological insulators
May 15, 2012 4:20 am | News | CommentsLawrence Berkeley National Laboratory theorists and experimenters have led in the exploration of the unique properties of topological insulators, where electrons may flow on the surface without resistance and with their spin orientations and directions intimately related. Recent research at beamline 12.0.1 of the Advanced Light Source opens the way to exciting prospects for practical new spintronic devices that exploit control of electron spin as well as charge.
Researchers map path to quantum electronic devices
May 14, 2012 4:28 am | News | CommentsA team of Duke University engineers has created a master "ingredient list" describing the properties of more than 2,000 compounds that might be combined to create the next generation of quantum electronics devices.
Topological insulator shows promise for new class of room-temperature electronics
May 8, 2012 5:43 am | News | CommentsIn the search for new materials with improved electrical conductivity, scientists at Brookhaven National Laboratory have found what appears to be a promising candidate. New experiments show that electrons on the surface of this so-called topological insulator are "protected" from two kinds of scattering that can potentially interfere with the flow of electric current, even at relatively "warm" room temperatures, where the flow of electricity was expected to break down.
Exotic material shows promise as flexible, transparent electrode
March 7, 2012 9:05 am | News | CommentsAn international team of scientists with roots at SLAC National Accelerator Laboratory and Stanford University has shown that ultrathin sheets of an exotic material, called topological insulators, remain transparent and highly conductive even after being deeply flexed 1,000 times and folded and creased like a piece of paper.
Bilayer graphene works as an insulator
January 24, 2012 9:56 am | News | CommentsA research team led by physicists at the University of California, Riverside has identified a property of bilayer graphene (BLG) that the researchers say is analogous to finding the Higgs boson in particle physics. The physicists report that in investigating BLG's properties they found that when the number of electrons on the BLG sheet is close to 0, the material becomes insulating.
Giant magnetoresistance can occur in a giant way without magnetism
January 19, 2012 5:46 am | News | CommentsPhase-change random access memory (PCRAM) is a promising technology for next-generation non-volatile memory, but it has been limited by room temperature efficiency. A research group in Japan recently invented a variation of PCRAM that achieves a magnetoresistance effect of more than 2000% at room temperature and higher, and doesn’t require the use of magnetic elements such as cobalt and platinum.
Electronics takes on a new spin
December 5, 2011 3:16 am | by David L. Chandler, MIT News Office | News | CommentsExotic materials called topological insulators, discovered just a few years ago, have yielded some of their secrets to a team of Massachusetts Institute of Technology researchers. For the first time, the team showed that light can be used to obtain information about the spin of electrons flowing over the material's surface, and has even found a way to control these electron movements by varying the polarization of a light source.
IBM, ABB collaborate to improve energy transmission
November 2, 2011 6:01 am | News | CommentsScientists at IBM and ABB are using supercomputers to study and potentially develop a new type of high-voltage insulator that will improve the efficiency of transmitting electricity. An improved insulator has the potential to transform the power grid by reducing energy loss and outages caused by material deterioration when exposed to weather.
Rigid restraint improves dielectric performance, lifespan
October 25, 2011 12:47 pm | News | CommentsJust as a corset improves the appearance of its wearer by keeping everything tightly together, new rigidly constraining insulating materials invented at Duke University helps prevent the inevitable microscopic breakdown of the “soft” polymers often used in their construction.
Unexpected magnetic excitations in doped insulator surprise researchers
October 24, 2011 4:46 am | News | CommentsWhen doping a disordered magnetic insulator material with atoms of a nonmagnetic material, the conventional wisdom is that the magnetic interactions between the magnetic ions in the material will be weakened. However, when the antiferromagnetic insulator barium manganate was doped, the barium manganate's magnetic excitations were surprisingly unreduced in strength and energy.
Wanted: 2011's Top Technologies
August 15, 2011 6:12 am | Blogs | CommentsThe editors of R&D Magazine have opened the nominations for the 2012 R&D 100 Awards competition, which will celebrate the 50th anniversary of the awards. If your organization introduced a new product this year, or is planning to, you can begin the entry process now.
Silicon technology improves efficiency of water delivery
June 8, 2011 12:28 pm | News | CommentsAs parts of the world struggle with water supplies under increasing pressure from fast-growing populations and changing climates, silicon technology in the form of pumps and membranes is helping farmers irrigate crops more efficiently. Dow Corning Corp., with industry partner Hemlock Semiconductor Group, is a major supplier of these products.
