AI 中文总结
该研究通过计算证实体相WN₂的两种六方相分别实现净与隐藏自旋-谷锁定，可抑制散射，获超高空穴迁移率，确立隐藏自旋极化的输运保护作用，扩展自旋-谷工程至中心对称半导体。
AI 中文摘要
室温下的高载流子迁移率是高性能电子器件的基础，但高迁移率空穴在体相半导体中仍较为罕见。自旋-谷锁定可抑制谷间散射并提升迁移率，不过仅适用于 inversion symmetry（空间反演对称性）破缺的材料。隐藏自旋极化提供了突破该限制的可能，但其补偿型自旋纹理能否保护电荷传输仍不明确。通过从头算电子-声子相互作用与输运计算，我们证实体相WN₂的两种六方相实现了净与隐藏自旋-谷锁定，并展现出超高室温空穴迁移率。在非中心对称的α-WN₂中，大的谷自旋分裂产生净自旋-谷锁定，几乎消除了声子介导的谷间散射；在中心对称的β-WN₂中，隐藏塞曼型自旋极化产生补偿的、分区域的自旋纹理，其在谷间反转，抑制谷间散射的效果与净锁定相当。刚性的W-N/N-N共价网络进一步使剩余的谷内散射保持较弱水平。我们的结果确立了隐藏自旋极化是一种有效的输运保护机制，并将自旋-谷工程扩展至中心对称体相半导体。
英文摘要
High carrier mobility at room temperature underpins high-performance electronics, yet high hole mobility remains rare in bulk semiconductors. Spin-valley locking can suppress intervalley scattering and enhance mobility, but it is limited to materials with broken inversion symmetry. Hidden spin polarization offers a possible route beyond this constraint, although whether its compensated spin textures could protect charge transport remains unclear. Using ab initio electron-phonon and transport calculations, we show that the two hexagonal phases of bulk WN$_2$ realize net and hidden spin-valley locking and exhibit ultrahigh room-temperature hole mobilities. In non-centrosymmetric $α$-WN$_2$, a large valley spin splitting produces net spin-valley locking that nearly eliminates phonon-mediated intervalley scattering. In centrosymmetric $β$-WN$_2$, hidden Zeeman-type spin polarization yields a compensated, sector-resolved spin texture that reverses between valleys and suppresses intervalley scattering as effectively as the net locking does. The stiff W-N/N-N covalent network further keeps the remaining intravalley scattering weak. Our results establish hidden spin polarization as an effective transport-protection mechanism and extend spin-valley engineering to centrosymmetric bulk semiconductors.
Comments7 pages, 4 figures
