Magnetic field Characterization of edge currents in quantum spin Hall insulators

Fuente: arXiv
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Main Authors: Pinto, Felipe, Heitzer, Ricardo C, Dvorquez, Eitan, Rodriguez, Roberto, Sun, Qiang, Greentree, Andrew D, Gibson, Brant C, Maze, Jeronimo R
Format: Preprint
Published: 2024
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_version_ 1866913580105859072
author Pinto, Felipe
Heitzer, Ricardo C
Dvorquez, Eitan
Rodriguez, Roberto
Sun, Qiang
Greentree, Andrew D
Gibson, Brant C
Maze, Jeronimo R
author_facet Pinto, Felipe
Heitzer, Ricardo C
Dvorquez, Eitan
Rodriguez, Roberto
Sun, Qiang
Greentree, Andrew D
Gibson, Brant C
Maze, Jeronimo R
contents Quantum spin Hall (QSH) insulators are materials with nontrivial topological properties, characterized by helical edge currents. In 2D strips, the application of a bias voltage along the edge generates a magnetization that can be measured using quantum sensors and magnetometry techniques. In this work, we calculate the magnetic field in the vicinity of the edge and explore the potential role of nitrogen-vacancy (NV) centers in diamond as local probes for the characterization of QSH edge states in topological insulators. We characterize the magnetic field near the edges produced by both electron currents and spin accumulation at the edge. We focus on identifying the position from the edge at which the effects of spin accumulation become detectable. We observe that a larger gap between the conduction and valence bands, along with a lower Fermi velocity, results in a stronger magnetic field, with the detectable spin accumulation being more concentrated near the edge. Conversely, a smaller gap results in a slight reduction in the magnetic field magnitude, but the field associated with spin accumulation becomes detectable further from the edge. This work provides insights that could be useful for the characterization of topological materials and the development of novel electro-optical devices.
format Preprint
id arxiv_https___arxiv_org_abs_2411_11701
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Magnetic field Characterization of edge currents in quantum spin Hall insulators
Pinto, Felipe
Heitzer, Ricardo C
Dvorquez, Eitan
Rodriguez, Roberto
Sun, Qiang
Greentree, Andrew D
Gibson, Brant C
Maze, Jeronimo R
Mesoscale and Nanoscale Physics
Quantum spin Hall (QSH) insulators are materials with nontrivial topological properties, characterized by helical edge currents. In 2D strips, the application of a bias voltage along the edge generates a magnetization that can be measured using quantum sensors and magnetometry techniques. In this work, we calculate the magnetic field in the vicinity of the edge and explore the potential role of nitrogen-vacancy (NV) centers in diamond as local probes for the characterization of QSH edge states in topological insulators. We characterize the magnetic field near the edges produced by both electron currents and spin accumulation at the edge. We focus on identifying the position from the edge at which the effects of spin accumulation become detectable. We observe that a larger gap between the conduction and valence bands, along with a lower Fermi velocity, results in a stronger magnetic field, with the detectable spin accumulation being more concentrated near the edge. Conversely, a smaller gap results in a slight reduction in the magnetic field magnitude, but the field associated with spin accumulation becomes detectable further from the edge. This work provides insights that could be useful for the characterization of topological materials and the development of novel electro-optical devices.
title Magnetic field Characterization of edge currents in quantum spin Hall insulators
topic Mesoscale and Nanoscale Physics
url https://arxiv.org/abs/2411.11701