The swing doctors: Physicist cracks code on material that works as both conductor, insulator

August 31, 2018 by Morgan Sherburne, University of Michigan
Pictured is a crystal of ytterbium dodecaboride, or YbB 12. Credit: University of Michigan

Quantum materials are a type of odd substance that could be many times more efficient at conducting electricity through our iPhones than the commonly used conductor silicon—if only physicists can crack how the stuff works.

A University of Michigan physicist has gotten one step closer with detailing a novel material, ytterbium dodecaboride, or YbB12, and imaging how efficiently electricity is conducted through this material. The demonstration of this material's conductivity will help contribute to scientists' understanding of the spin, charge, and in these electromagnetic materials.

YbB12 is a very clean crystal that is unusual in it shares the properties of both conductors and insulators. That is, the bulk interior of YbB12 is an insulator and doesn't conduct electricity, while its surface is extraordinarily efficient at conducting electricity. But researchers needed to be able to measure exactly how good at conducting electricity this material is.

"Right now, we are using a phone to talk. Inside the phone are its key parts: a transistor made of silicon that passes electricity through the device," said project leader Lu Li, U-M associate professor of physics. "These silicon semiconductors use the bulk of their own material to make a path for electric current. That makes it difficult to make electronic devices faster or more compact."

Replacing a phone's silicon transistors with ones made of would make the phone much faster—and much lighter. That's because the transistors inside the device would conduct electricity very quickly on their surfaces, but could be made much smaller, with a lighter core beneath a layer of the metal's insulating interior.

Quantum would not be limited to powering our phones. They could be used in quantum computing, a field still in its infancy, but which could be used for cybersecurity. Our computers currently work by processing data in binary digits: 0 and 1. But there's a limit to how fast computers can process data in this way. Instead, quantum computers would use the quantum properties of atoms and electrons to process information, opening up the ability to process huge volumes of information much faster.

Resistance oscillation reveals the electronic structure of YbB 12 . Credit: University of Michigan

Li studied YbB12 to understand the material's electronic signature, which tells researchers how well a material conducts electricity. In a clean metal that conducts electricity very efficiently, electrons form clusters within the metals.

The swings of these clusters lead to oscillations of the electrical resistance of the material. This oscillation tells researchers how efficiently the material is able to conduct . In this study, Li was able to measure the oscillation of resistance of a bulk insulator, a problem he's been trying to solve for four years.

To measure this oscillation, Li used a very powerful magnet located in a lab at the National High Magnetic Field Laboratory in Florida. This magnet is similar to a magnet you would use to fix a photo to your refrigerator, says Li, but many times more powerful. A fridge magnet has a pull of about 0.1 Tesla, a unit of measurement for the . The magnet at the Florida laboratory has a pull of 45 Tesla. That's about 40 times more powerful than the magnet used in an MRI machine.

To measure the efficiency of YbB12, Li ran an electric current through the sample in the presence of the magnet. Then, he examined how much the electric voltage dropped throughout the sample. That told Li how much resistance was present in the material.

"We finally got the right evidence. We found a material that was a good insulator on its interior, but at its surface was a good conductor—so good that we can make an electric circuit on that conductor," Li said. "You can imagine that you can have a circuit that moves as fast as imaginable on a teeny, tiny surface. That's what we hope to achieve for future electronics."

The study appears online in the journal Science.

Explore further: Research could lead to more efficient electronics

More information: Z. Xiang et al. Quantum oscillations of electrical resistivity in an insulator, Science (2018). DOI: 10.1126/science.aap9607

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1 / 5 (1) Sep 02, 2018
"Quantum materials are a type of odd substance that could be many times more efficient at conducting electricity through our iPhones than the commonly used conductor silicon—if only physicists can crack how the stuff works."

That is very wrong as silicon is intrinsically an insulator and NOT a conductor unless altered with a doping agent.

not rated yet Sep 05, 2018
not rated yet Sep 07, 2018
there is no such thing as a quantum; concepts, reality r two different things
not rated yet Sep 07, 2018
Oxidation is the Relative Cumulative Field; Given Stability; therefore, the objects, i.e. Physical Center and Strength(amplitude), .... or E(P)! Every point! Get it, little tiny equal potential spheres. Can't be as hard as you describe. describe the field at every point in space and time

Easier to visualize 'atomically' set a unit less isomorphic space where time stands still, i.e. c = 1, T = Lambda. get it Lambda is ref updates all shown to the cpu. Should be able to better define the periodic table as N Pairs. By the way, it's only multiple slides of the same thing overlaid
not rated yet Sep 07, 2018
Fields don't bother fields, only add; but field centers move in response. The response to the center moving requires each potential surface to be updated relative to the center. Note, every center! So define your dance, using LOGIC! I ain't got no tools and ain't got no money; but, I got lots of Logic or Sense! Love to juz follow a smarter team! Start with Hydrogen, a Neutron is a Proton and an Electron at the same point and every center responds to the field at each Hypothetical point in Space-time, so each point requires a set of attributes. I would make these attributes objects. meh
not rated yet Sep 07, 2018
Silly Wabbits! Each state defines all .. 'less u show control
not rated yet Sep 08, 2018
If you've been following me; you are aware of a suggestion; An isomorphic mathematical space, i.e. c=1, T=Lambda is a ref then ref scale; every point has a set of attributes updated at each Clock cycle. Think of each point as an object that you may zoom in or out while time stands still! Each Point either a center or ...think holistically!
not rated yet Sep 08, 2018
QM is a tool; a tool that you supply the logic of chance, meh. Not my idea of science, more like an Easter Egg Hunt Through Fantasy Land; no offense intended; suggest review of your logic!

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