Topological-metal nanostructures
Final Report Abstract
The project focuses on understanding and manipulating the behavior of topological metals, a class of materials featuring quantum-anomalous electronic properties. These materials hold promise for future technological applications due to their peculiar transport phenomena. However, understanding the behavior of these materials at the theoretical level poses challenges, particularly regarding the effect of spatial confinement in topological-metal based nanostructures. This oneyear project aimed to develop theoretical tools to study such systems. Specifically, the focus was on predicting novel transport phenomena by considering the response of nanostructures to electromagnetic fields and the influence of superconductivity when these materials are brought in contact with a conventional superconductor. The research resulted in significant findings, including the discovery of a novel metallic state called the Fermi-arc metal in specific superstructures of topological metals. Additionally, investigations of electron transport along specific surface states at interfaces between different topological metals revealed intriguing quantum phenomena, such as universal conductance and magnetic breakdown. Although the discovery of Fermi-arc metals shifted the main research focus from spatially confined systems towards spatially extended superstructures, one subproject was completed exactly in accord with the research plan. This study investigated the photogalvanic effect in confined topological metals, where we explored how to induce and control this effect in topological metals by designing the material’s surface. The findings show how the photocurrent is influenced by the arrangement of surface states, making the behavior more complex and potentially useful than in bulk systems. In terms of future applications, these results may be useful for the construction of photodetectors and other electronic devices.
Publications
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Fermi-Arc Metals. Physical Review Letters, 130(19).
Breitkreiz, Maxim & Brouwer, Piet W.
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“Magnetic Breakdown and Chiral Magnetic Effect at Weyl-Semimetal Tunnel Junctions”. Phys. Rev. B 107, L241109
A. Y. Chaou, V. Dwivedi & M. Breitkreiz
