AI 中文总结
该研究提出立方Dresselhaus轨道耦合可使轨道霍尔电导率提升一个数量级以上，其发散系数为线性耦合的17倍，为巨轨道霍尔响应及轨道电子器件应用提供新途径。
AI 中文摘要
轨道贝里曲率（OBC）决定了本征轨道霍尔电导率（OHC），这是轨道电子学中的核心物理量。此前增强OHC的方法主要依赖线性动量相关的Rashba型轨道耦合。本文证明立方Dresselhaus轨道耦合为增强OHC提供了新途径。采用有效双轨道能带模型，研究发现立方耦合会在动量空间产生纯线性耦合不存在的热点，这些热点处的OBC显著增强；这种局域增强结合热点的多重性，使OHC比线性耦合情形提升一个数量级以上。进一步研究表明，在小能级分裂极限下，OHC与能级分裂成反比发散，其发散系数是线性情形的17倍，这些结果确立了立方Dresselhaus耦合是实现巨轨道霍尔响应的有效途径，为轨道电子器件应用开辟了新方向。
英文摘要
The orbital Berry curvature (OBC) governs the intrinsic orbital Hall conductivity (OHC), a central quantity in orbitronics. Previous approaches for enhancing the OHC have primarily relied on a linearin-momentum, Rashba-type orbital coupling. Here, we show that cubic Dresselhaus orbital coupling offers a new route to enhancing the OHC. Using an effective two-orbital band model, we show that the cubic coupling generates momentum-space hot spots, absent in the purely linear case, at which the OBC is strongly enhanced. This local enhancement, together with the multiplicity of the hot spots, boosts the OHC by more than an order of magnitude relative to the linear-coupling value. We further find that the OHC diverges inversely with the level splitting in the small-splitting limit, with a divergence coefficient universally seventeen times larger than that of the linear case. These results establish cubic Dresselhaus coupling as a route to giant orbital Hall responses, opening new avenues for orbitronic device applications.
Comments7 pages, 4 figures, and supplementary material will be provided in a published version
