Spectroscopic evidence for spin-polarized edge states in graphitic Si nanowires

Abstract

The step edges on the Si(553)-Au surface undergo a 1 x 3 reconstruction at low temperature which has recently been interpreted theoretically as the x3 ordering of spin-polarized silicon atoms at the edges of the graphitic Si nanowires on this vicinal surface. This predicted magnetic ground state has a clear spectroscopic signature - a silicon step-edge state at 0.5 eV above the Fermi level - that arises from strong exchange splitting and hence would not occur without spin polarization. Here we report spatially resolved scanning tunneling spectroscopy data for these nanowires. At low temperature we find an unoccupied state at 0.5 eV above every third step edge silicon atom, in excellent agreement with the spin-polarized ground state predicted theoretically. This spin-polarized state survives up to room temperature where the position of the spins rapidly fluctuates among all Si step-edge sites.

References in corpus (3)

• Emergence of magnetism in graphene materials and nanostructures
• Room-temperature ferromagnetism in graphite driven by 2D networks of point defects
• Intrinsic magnetism at silicon surfaces

Cited by in corpus (7)

• Evidence for Long-Range Spin Order Instead of a Peierls Transition in Si(553)-Au Chains
• Spin Chains and Electron Transfer at Stepped Silicon Surfaces
• Plasmon Standing Waves by Oxidation of Si(553)-Au
• Current-Dependent Periodicities of Si(553)-Au
• States decoupled from the surface in short Si atomic chains
• Mechanical Properties of Au Coated Si Nanowafer: an Atomistic Study
• Temperature dependent ARPES of the metallic-like bands in Si(553)-Au