Quantum Imaging of Topologically Unpaired Spin-Polarized Dirac Fermions
Abstract
The motion of a relativistic particle is linked to its spin by the Dirac equation. Remarkably, electrons in two-dimensional materials can mimic such Dirac particles but must always appear in pairs of opposite spin chirality. Using topological ideas of chiral boundary electrons wrapping a three-dimensional crystal with tuned spin-orbit coupling, we show that elusive unpaired Dirac fermions exist on the surface of a topological insulator parent matrix, pure antimony. Using scanning tunneling microscopy and angle-resolved photoemission spectroscopy we image coherent quantum interference between these particles, map their helical spin texture, and ultimately observe a transition to a single Dirac fermion distinguished by backscattering suppression via Berry phase interference. The robust dynamics of these unique spin-polarized carriers envisage future applications in spintronics and topological quantum computation.
Keywords
Cite
@article{arxiv.0909.0921,
title = {Quantum Imaging of Topologically Unpaired Spin-Polarized Dirac Fermions},
author = {Kenjiro K. Gomes and Wonhee Ko and Warren Mar and Yulin Chen and Zhi-Xun Shen and Hari C. Manoharan},
journal= {arXiv preprint arXiv:0909.0921},
year = {2009}
}
Comments
Updated from original (copy of earlier journal submission) to include references and context to latest published and posted experiments involving STM and ARPES