Intrinsic magnetism at silicon surfaces

TL;DR

This paper demonstrates theoretically that certain silicon surfaces with nanoscale graphitic step edges can exhibit intrinsic magnetism, opening new possibilities for spin-based electronics in silicon.

Contribution

It reveals the existence of intrinsic magnetism in silicon surfaces with graphitic step edges, a novel finding in a nonmagnetic material.

Findings

Magnetism is linked to nanoscale graphitic structures on silicon surfaces.

Theoretical evidence supports magnetic states at silicon step edges.

Potential for silicon-based spintronic applications.

Abstract

It has been a long-standing goal to create magnetism in a nonmagnetic material by manipulating its structure at the nanometer scale. This idea may be realized in graphitic carbon: evidence suggests magnetic states at the edges of graphene ribbons and at grain boundaries in graphite. Such phenomena have long been regarded as unlikely in silicon because there is no graphitic bulk phase. Here we show theoretically that intrinsic magnetism indeed exists in a class of silicon surfaces whose step edges have a nanoscale graphitic structure. This magnetism is intimately connected to recent observations, including the coexistence of double- and triple-period distortions and the absence of edge states in photoemission. Magnetism in silicon may ultimately provide a path toward spin-based logic and storage at the atomic level.