New Material Pushes Limits of Superconductivity’s ‘Cousin’
+ For decades, scientists have hunted for materials in which electrons flow without resistance. Until recently, this hunt focused squarely on superconductors, in which electrons pair off and flow freely. But superconductors aren’t the only game in town. In 2013, for the first time scientists observed a phenomenon known as the quantum anomalous Hall (QAH) effect. Just like in a superconductor, electrons under the QAH effect flow without dissipating energy, albeit via a different mechanism. Now a new material is pushing the QAH effect to new limits, dramatically increasing the temperature and conditions in which the effect occurs.
“While we’re not looking at applications yet, the combination of increased temperature and the novelty of this effect happening in a metal opens up a wide array of new possibilities,” Georgescu says. “It’s exciting.”
+ The new material edges the QAH effect toward viability in applications such as quantum computers, says study co-author Jennifer Cano, an affiliate associate research scientist at the Flatiron Institute’s Center for Computational Quantum Physics (CCQ) in New York City.
+ Looking at the Hall effect at the quantum level, you’ll find that the electrons move in discrete channels through the material. “Similar to how separated highway lanes allow for faster vehicle transit, the discrete channels allow for more efficient transfer of electrons,” says Georgescu. “The paths protect the electrons from smashing into other electrons and slowing down and losing energy.”
+ The need for a strong external magnetic field limits the utility of the Hall effect. But with the QAH effect, no external magnetic field is needed. Instead, the material provides its own magnetic field.
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