Long-range perturbation of helical edge states by nonmagnetic defects in two-dimensional topological insulators

Sablikov Vladimir A. Long-range perturbation of helical edge states by nonmagnetic defects in two-dimensional topological insulators. Physical Review B , 2020 , 102 (7). ISSN 2469-9950

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PhysRevB.102.075434(2020) Sablikov-Long-range perturbation of helical edge states by nonmagnetic defects in 2d TIs.pdf

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Официальный URL: https://doi.org/10.1103/PhysRevB.102.075434

Аннотация

We study the electronic states that are formed due to the tunnel coupling between helical edge states (HESs) and bound states of nonmagnetic point defects in two-dimensional topological insulators in the general case of broken axial spin symmetry. It is found that the coupling of HESs and a single defect leads to the formation of composite HESs composed of the bound states and a set of the conventional HESs. Their spectral density near the defect has a resonance shifted relative to the energy level of the bound state. But of most importance is a long-range perturbation of the HESs around the defect, which is a cloud consisting of both Kramers partners of conventional edge states. Therefore each of the composite HESs contains both the right- and left-moving conventional HESs. The amplitude of this perturbation decreases inversely with the distance from the defect. In a system of many defects, this perturbation leads to a long-range coupling between bound states of different defects mediated by the HESs and causes amazing effects. We study these effects for a two-defect system where the proposed mechanism of indirect coupling leads to a splitting of the resonances of isolated defects even if the distance between them is very large. As a result an asymmetric structure of two-peak resonance arises that very unusually changes with the distance between the defects.

Тип объекта: Статья
Авторы на русском. ОБЯЗАТЕЛЬНО ДЛЯ АНГЛОЯЗЫЧНЫХ ПУБЛИКАЦИЙ!: Сабликов В.А.
Подразделения (можно выбрать несколько, удерживая Ctrl): 199 лаб. теоретических проблем микроэлектроники
URI: http://cplire.ru:8080/id/eprint/7896
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