This Strange New Crystal Could Power the Next Leap in Quantum Computing

A newly discovered crystal, which they're calling platinum-bismuth-two (PtBi2), is overturning what scientists thought they knew about superconductivity. And only the top-and bottommost surfaces of the lustrous gray crystal are able to carry supercurrent without resistance, while the bulk remains ordinary metal. The electrons on the surfaces form pairs with an unusual sixfold pattern, unlike any known superconductor, breaking longstanding rules. And yet, the edges of this crystal naturally harbor Majorana particles, long-hypothesized entities that are thought to make for particularly robust qubits in a quantum computer. Researchers described PtBi₂ as a natural topological superconductor and one of the clearest examples yet of this rare material type.

Edge-Only Superconductivity in PtBi₂ Offers Pathway for Topological Quantum Computing

According to a study (via Phys.org) by IFW Dresden and the Cluster of Excellence ct.qmat, surface electrons are confined due to the crystal's topological properties, remaining paired even if the crystal is sliced. At low temperatures, these electrons enable superconductivity only on the surfaces, while the interior behaves like a normal metal. High-resolution measurements showed electrons along six specific directions do not pair, reflecting the atomic symmetry of PtBi₂.

The superconductivity that occurs spontaneously traps Majorana particles at the edges, and these could be manipulated to take topological quantum computing forward, as mentioned by Prof Jeroen van den Brink.

Manipulating PtBi₂ Could Unlock Majorana Particles for Quantum Technology Advances

Scientists are now investigating strategies for taming these effects, such as by making the crystal thinner or subjecting it to magnetic fields that may push Majoranas toward corners and lock them away from regular electrons.

PtBi2 hence serves as a promising ground for fundamental physics as well as future quantum devices, with its superconductivity and particle property previously out of reach.