Topological insulators have been of great interest to physicists in recent years because of unusual properties that may provide insights into quantum physics. But most analysis of such materials has had to rely on highly simplified models. Now, a team of researchers at Massachusetts Institute of Technology has performed a more detailed analysis that hints at the existence of six new kinds of topological insulators.
By applying pressure to a semiconductor, researchers have been able to transform a semiconductor...
A single layer of tin atoms could be the world’s first material to conduct electricity with 100...
Researchers at Massachusetts Institute of Technology have succeeded in producing and measuring a coupling of photons and electrons on the surface of an unusual type of material called a topological insulator. This type of coupling had been predicted by theorists, but never observed.
A theoretical study conducted by scientists at Japan’s National Institute of Materials Science reveals the possibility of developing a quantum material to transport zero-resistance edge current above room temperature. This capability, allowed by large spin-orbit coupling, will depend on the construction of a new class of topological materials that the researchers have designed.
An international collaboration at Lawrence Berkeley National Laboratory’s Advanced Light Source has induced high-temperature superconductivity in a toplogical insulator, an important step on the road to fault-tolerant quantum computing.
When scientists found electrical current flowing where it shouldn't be—at the place where two insulating materials meet—it set off a frenzy of research that turned up more weird properties and the hope of creating a new class of electronics. Now scientists have mapped those currents in microscopic detail and found another surprise: Rather than flowing uniformly, the currents are stronger in some places than others.
Researchers not only confirmed several theoretical predictions about topological crystalline insulators (TCIs), but made a significant experimental leap forward that revealed even more details about the crystal structure and electronic behavior of these newly identified materials. The findings reveal the unexpected level of control TCIs can have over electrons by creating mass.
Researchers from the RIKEN Center for Life Science Technologies and Chiba Univ. have developed a high-temperature superconducting wire with an ultrathin polyimide coating only 4 micrometers thick, more than 10 times thinner than the conventional insulation used for high-temperature superconducting wires. The breakthrough should help the development of more compact superconducting coils for medical and scientific devices.
It is well known to scientists that the three common phases of water (ice, liquid and vapor) can exist stably together only at a particular temperature and pressure, called the triple point. Scientists now have made the first-ever accurate determination of a solid-state triple point in a substance called vanadium dioxide, which is known for switching rapidly from an electrical insulator to a conductor.
New research shows that a class of materials being eyed for the next generation of computers behaves asymmetrically at the sub-atomic level. This research is a key step toward understanding the topological insulators that may have the potential to be the building blocks of a super-fast quantum computer that could run on almost no electricity.
A team of theoretical physicists at the U.S. Naval Research Laboratory and Boston College has identified cubic boron arsenide as a material with an extraordinarily high thermal conductivity and the potential to transfer heat more effectively from electronic devices than diamond, the best-known thermal conductor to date.
Researchers have made the first direct images of electrical currents flowing along the edges of a topological insulator. In these strange solid-state materials, currents flow only along the edges of a sample while avoiding the interior. Using an exquisitely sensitive detector they built, the team was able to sense the weak magnetic fields generated by the edge currents and tell exactly where the currents were flowing.
By means of special metamaterials, light and sound can be passed around objects. Researchers have now succeeded in demonstrating that the same materials can also be used to specifically influence the propagation of heat. They have built a structured plate of copper and silicon that conducts heat around a central area without the edge being affected.
Researchers 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.
Electrons 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.
Unlike conventional electrical insulators, which do not conduct electricity, topological insulators have the unique property of conducting electricity on their surface, while acting as an insulator inside. In a step toward understanding and exploiting an exotic form of matter that has been sparking excitement for potential applications in a new genre of supercomputers, scientists are reporting the first identification of a naturally occurring topological insulator that was retrieved from an abandoned gold mine in the Czech Republic.
University 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.
Researchers have tried for decades to replicate the effects of transistors in transition metal oxides by using a voltage to convert the material from an insulator to a metal, but the induced change only occurs within a few atomic layers of the surface. Recently, however, scientists in Japan have discovered that applying a voltage to a vanadium dioxide film several tens of nanometers thick converts the entire film from an insulator to a metal.
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.
Rice 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.
Researchers 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.
By 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.
The 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.
For 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.
Topological 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.
A 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.
If 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.
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