Tunable Quantum Anomalous Hall Effect via Crystal Order in Spin-Splitting Antiferromagnets

Fuente: arXiv
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Autores principales: Zhu, Wenxuan, Bai, Hua, Han, Lei, Pan, Feng, Song, Cheng
Formato: Preprint
Publicado: 2024
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author Zhu, Wenxuan
Bai, Hua
Han, Lei
Pan, Feng
Song, Cheng
author_facet Zhu, Wenxuan
Bai, Hua
Han, Lei
Pan, Feng
Song, Cheng
contents Quantum anomalous Hall (QAH) effect provides dissipationless chiral channels for spin transport, expected as an outstanding candidate in future low-power quantum computation. The spin-splitting band structure is vital for obtaining QAH effect in topological systems, with ferromagnetism indispensable to manipulate the Chern number. Herein, we challenge this wisdom by proposing tunable QAH effect in spin-splitting antiferromagnets with zero magnetization. Since the spin splitting of these unique magnets originates from the alternate crystal environment, the Chern number can be modulated not only by the conventional magnetic order, but also by the crystal order, opening an additional dimension for tuning QAH effect. Our concept is illustrated based on two-dimensional (2D) MnBi2Te4 (MBT) with even septuple layers (SLs), a typical axion insulator with fully magnetic compensation. By interlayer rotation and translation operations, sublattices of MBT with opposite magnetizations are no longer connected by inversion or mirror symmetries, leading to the transition to the QAH insulator. The flexible stacking of 2D materials enables the reversible Chern number by crystal design. Our work fundamentally reveals the crystal-order-dependent QAH effect in spin-splitting antiferromagnets, which would advance QAH effect-based devices towards high controllability, integration density and operation speed.
format Preprint
id arxiv_https___arxiv_org_abs_2410_16587
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Tunable Quantum Anomalous Hall Effect via Crystal Order in Spin-Splitting Antiferromagnets
Zhu, Wenxuan
Bai, Hua
Han, Lei
Pan, Feng
Song, Cheng
Mesoscale and Nanoscale Physics
Materials Science
Quantum anomalous Hall (QAH) effect provides dissipationless chiral channels for spin transport, expected as an outstanding candidate in future low-power quantum computation. The spin-splitting band structure is vital for obtaining QAH effect in topological systems, with ferromagnetism indispensable to manipulate the Chern number. Herein, we challenge this wisdom by proposing tunable QAH effect in spin-splitting antiferromagnets with zero magnetization. Since the spin splitting of these unique magnets originates from the alternate crystal environment, the Chern number can be modulated not only by the conventional magnetic order, but also by the crystal order, opening an additional dimension for tuning QAH effect. Our concept is illustrated based on two-dimensional (2D) MnBi2Te4 (MBT) with even septuple layers (SLs), a typical axion insulator with fully magnetic compensation. By interlayer rotation and translation operations, sublattices of MBT with opposite magnetizations are no longer connected by inversion or mirror symmetries, leading to the transition to the QAH insulator. The flexible stacking of 2D materials enables the reversible Chern number by crystal design. Our work fundamentally reveals the crystal-order-dependent QAH effect in spin-splitting antiferromagnets, which would advance QAH effect-based devices towards high controllability, integration density and operation speed.
title Tunable Quantum Anomalous Hall Effect via Crystal Order in Spin-Splitting Antiferromagnets
topic Mesoscale and Nanoscale Physics
Materials Science
url https://arxiv.org/abs/2410.16587