Like some advanced artificial materials, kawazulite
conducts electricity at its surface but not in its bulk.


Lab-made supermaterial that could boost computing exists in nature too

Naturally occurring topological insulator is cleaner than synthetic samples.

Zeeya Merali
08 March 2013

They say it’s what is on the inside that counts. But that is not true for topological insulators — exotic materials that conduct electricity only along their surfaces. Physicists have now demonstrated this property in a naturally occurring mineral for the first time1.

Their findings could boost efforts to build spintronic devices — in which currents are driven by an intrinsic property of electrons called spin, rather than by voltages. The results could also help the design of quantum computers that would use spin to encode information.

Predicted to exist in 2005, topological insulators were first synthesized from heavy elements in 2008. Their odd conducting abilities arise because each electron’s spin becomes coupled to its motion. This relationship compels the electrons to circle around on the spot, preventing them from moving through the bulk material, so that they cannot conduct electricity.

But at the material’s edge, the electrons do not have enough space for this circling motion; instead, they are forced to hop along the surface in semicircular jumps, enabling conduction.

Read more: Lab-made supermaterial that could boost computing exists in nature too : Nature News & Comment.

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