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| Main Authors: | , |
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| Format: | Preprint |
| Published: |
2025
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| Subjects: | |
| Online Access: | https://arxiv.org/abs/2509.00430 |
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| _version_ | 1866915985087266816 |
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| author | Zhang, Xin Zhang, Shihao |
| author_facet | Zhang, Xin Zhang, Shihao |
| contents | Altermagnets, a newly discovered class of materials, exhibit zero net magnetization while hosting spin-split electronic bands. However, monolayer altermagnets maintain degenerate band gaps at the high-symmetry X and Y points in the Brillouin zone, manifesting a paravalley phase characterized by unpolarized valley states. In this work, we demonstrate that spontaneously broken valley degeneracy can be achieved through interlayer sliding in engineered M$_2$A$_2$B and M$_2$AA$'$B bilayer altermagnets by first-principles calculations and minimal microscopic model. We propose a promising route to achieve antiferromagnetic half-metal driven by sliding and emergent ferrovalley phase without applied electric field, which is realized in the V$_2$SSeO engineered bilayer. Our calculations also reveal that Mo$_2$O$_2$O exhibits the largest valley splitting gap of ~0.31 eV, making it a promising candidate for valley-spin valve devices. Furthermore, band structure calculations on Mo$_2$AA$'$O materials demonstrate that increasing the difference in atomic number ($Δ$Z) between A and A$'$ site atoms effectively enhances valley polarization. This work establishes a novel platform for discovering and controlling ferrovalley states in altermagnetic systems. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2509_00430 |
| institution | arXiv |
| publishDate | 2025 |
| record_format | arxiv |
| spellingShingle | Sliding-induced ferrovalley polarization and possible antiferromagnetic half-metal in bilayer altermagnets Zhang, Xin Zhang, Shihao Materials Science Mesoscale and Nanoscale Physics Altermagnets, a newly discovered class of materials, exhibit zero net magnetization while hosting spin-split electronic bands. However, monolayer altermagnets maintain degenerate band gaps at the high-symmetry X and Y points in the Brillouin zone, manifesting a paravalley phase characterized by unpolarized valley states. In this work, we demonstrate that spontaneously broken valley degeneracy can be achieved through interlayer sliding in engineered M$_2$A$_2$B and M$_2$AA$'$B bilayer altermagnets by first-principles calculations and minimal microscopic model. We propose a promising route to achieve antiferromagnetic half-metal driven by sliding and emergent ferrovalley phase without applied electric field, which is realized in the V$_2$SSeO engineered bilayer. Our calculations also reveal that Mo$_2$O$_2$O exhibits the largest valley splitting gap of ~0.31 eV, making it a promising candidate for valley-spin valve devices. Furthermore, band structure calculations on Mo$_2$AA$'$O materials demonstrate that increasing the difference in atomic number ($Δ$Z) between A and A$'$ site atoms effectively enhances valley polarization. This work establishes a novel platform for discovering and controlling ferrovalley states in altermagnetic systems. |
| title | Sliding-induced ferrovalley polarization and possible antiferromagnetic half-metal in bilayer altermagnets |
| topic | Materials Science Mesoscale and Nanoscale Physics |
| url | https://arxiv.org/abs/2509.00430 |