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arXiv · 0909.0921

Quantum Imaging of Topologically Unpaired Spin-Polarized Dirac Fermions

Kenjiro K. Gomes·Wonhee Ko·Warren Mar·Yulin Chen·Zhi-Xun Shen·Hari C. Manoharan
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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.

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Kenjiro K. Gomes, Wonhee Ko, Warren Mar, Yulin Chen, Zhi-Xun Shen, Hari C. Manoharan. 2009-09-24. Quantum Imaging of Topologically Unpaired Spin-Polarized Dirac Fermions. https://arxiv.org/abs/0909.0921

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