Symmetry-Indicated Time-Reversal-Doubled Axion Insulators
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arXiv
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| Autori principali: | , , , , , , |
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| Natura: | Preprint |
| Pubblicazione: |
2026
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| _version_ | 1866908859060191232 |
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| author | Xie, Yue Sheng, Haohao Wu, Quansheng Dai, Xi Fang, Zhong Weng, Hongming Wang, Zhijun |
| author_facet | Xie, Yue Sheng, Haohao Wu, Quansheng Dai, Xi Fang, Zhong Weng, Hongming Wang, Zhijun |
| contents | The axion insulator exhibits a topological magnetoelectric effect characterized by an axion angle $θ=π$, while the time-reversal-doubled axion insulator (T-DAXI) can be viewed as two copies of an axion insulator related by time-reversal symmetry. In this work, we show that a topological crystalline insulator with nonsymmorphic glide or screw symmetry hosts the T-DAXI phase. The spin-resolved topology of the T-DAXI phase is guaranteed by the nonsymmorphic symmetry invariant $δ_g=1$ or $δ_s=1$ in certain spin directions. In this phase, the partial axion angles are quantized to $π$, and the gapped surfaces realize half-quantized quantum spin Hall states. By applying an external magnetic field along the $z$ direction, electrons with opposite spins accumulate on opposite $(001)$ surfaces, producing a topological spin polarization in real space. When the magnetic field is time-periodic, this leads to an alternating spin current detectable in experiment. Using $\mathrm{\textit{ab initio}}$ calculations, we demonstrate that mixed bismuth monohalides Bi4Br3I and Bi4BrI3 realize the nonsymmorphic T-DAXI with $δ_g=δ_s=1$. Our findings not only reveal the symmetry-enforced T-DAXIs in nonsymmorphic topological crystalline insulators, but also introduce the spin magnetoelectric effect as a novel topological spin response. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2603_01072 |
| institution | arXiv |
| publishDate | 2026 |
| record_format | arxiv |
| spellingShingle | Symmetry-Indicated Time-Reversal-Doubled Axion Insulators Xie, Yue Sheng, Haohao Wu, Quansheng Dai, Xi Fang, Zhong Weng, Hongming Wang, Zhijun Materials Science The axion insulator exhibits a topological magnetoelectric effect characterized by an axion angle $θ=π$, while the time-reversal-doubled axion insulator (T-DAXI) can be viewed as two copies of an axion insulator related by time-reversal symmetry. In this work, we show that a topological crystalline insulator with nonsymmorphic glide or screw symmetry hosts the T-DAXI phase. The spin-resolved topology of the T-DAXI phase is guaranteed by the nonsymmorphic symmetry invariant $δ_g=1$ or $δ_s=1$ in certain spin directions. In this phase, the partial axion angles are quantized to $π$, and the gapped surfaces realize half-quantized quantum spin Hall states. By applying an external magnetic field along the $z$ direction, electrons with opposite spins accumulate on opposite $(001)$ surfaces, producing a topological spin polarization in real space. When the magnetic field is time-periodic, this leads to an alternating spin current detectable in experiment. Using $\mathrm{\textit{ab initio}}$ calculations, we demonstrate that mixed bismuth monohalides Bi4Br3I and Bi4BrI3 realize the nonsymmorphic T-DAXI with $δ_g=δ_s=1$. Our findings not only reveal the symmetry-enforced T-DAXIs in nonsymmorphic topological crystalline insulators, but also introduce the spin magnetoelectric effect as a novel topological spin response. |
| title | Symmetry-Indicated Time-Reversal-Doubled Axion Insulators |
| topic | Materials Science |
| url | https://arxiv.org/abs/2603.01072 |