Tunable corner states in topological insulators with long-range hoppings and diverse shapes

Fuente: arXiv
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Main Authors: Qin, Fang, Chen, Rui
Format: Preprint
Published: 2025
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author Qin, Fang
Chen, Rui
author_facet Qin, Fang
Chen, Rui
contents In this work we develop a theoretical framework for the control of corner modes in higher-order topological insulators (HOTIs) featuring long-range hoppings and diverse geometries, enabling precise tunability of their spatial positions. First, we demonstrate that the locations of corner states can be finely tuned by varying long-range hoppings in a circular HOTI, as revealed by a detailed edge theory analysis and the condition of vanishing Dirac mass. Moreover, we show that long-range hoppings in different directions (e.g., $x$ and $y$) have distinct effects on the positioning of corner states. Second, we investigate HOTIs with various polygonal geometries and find that the presence and location of corner modes depend sensitively on the shape. In particular, a corner hosts a localized mode if the Dirac masses of its two adjacent edges have opposite signs, while no corner mode emerges if the masses share the same sign. Our findings offer a versatile approach for the controlled manipulation of corner modes in HOTIs, opening avenues for the design and implementation of higher-order topological materials.
format Preprint
id arxiv_https___arxiv_org_abs_2506_12467
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Tunable corner states in topological insulators with long-range hoppings and diverse shapes
Qin, Fang
Chen, Rui
Mesoscale and Nanoscale Physics
In this work we develop a theoretical framework for the control of corner modes in higher-order topological insulators (HOTIs) featuring long-range hoppings and diverse geometries, enabling precise tunability of their spatial positions. First, we demonstrate that the locations of corner states can be finely tuned by varying long-range hoppings in a circular HOTI, as revealed by a detailed edge theory analysis and the condition of vanishing Dirac mass. Moreover, we show that long-range hoppings in different directions (e.g., $x$ and $y$) have distinct effects on the positioning of corner states. Second, we investigate HOTIs with various polygonal geometries and find that the presence and location of corner modes depend sensitively on the shape. In particular, a corner hosts a localized mode if the Dirac masses of its two adjacent edges have opposite signs, while no corner mode emerges if the masses share the same sign. Our findings offer a versatile approach for the controlled manipulation of corner modes in HOTIs, opening avenues for the design and implementation of higher-order topological materials.
title Tunable corner states in topological insulators with long-range hoppings and diverse shapes
topic Mesoscale and Nanoscale Physics
url https://arxiv.org/abs/2506.12467