发表机构
Norwegian University of Science and Technology (NTNU); Brock University（挪威科技大学; 布鲁克大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本文针对扭转双层石墨烯，分析其纹理化微狄拉克锥的局域相空间贝里曲率，明确几何响应峰值的局域填充值，建立局域解析框架以区分TBG相关的各类要素。
AI 中文摘要
扭转双层石墨烯中的小扭转角与异质应变纹理为相空间贝里几何提供了天然途径。我们表明，在一致处理自旋联络的情况下，纯几何四元数/位移部分不会产生混合贝里曲率；相比之下，扭转双层石墨烯中经投影的纹理化微狄拉克锥会获得真实的混合相空间曲率。我们分析了具有一维纹理和镜像Mₓ的可控局域霍尔条极限，在该极限下，赝规范梯度仅重整化沿纹理方向的纵向电导率，而直流非线性霍尔响应仅在额外的谷奇倾斜产生贝里曲率偶极子时出现。两种几何响应在相同局域填充μₗₒc=√2 m处达到峰值，为其共同起源提供了门可调指纹。所有局域锥参数及其纹理 susceptibility 均从θ=1.3°下的异质应变Bistritzer-MacDonald模型中提取，输运估计中用到的倾斜对应仅0.03%-0.2%的异质应变，低于器件中常规成像的数值。所得理论为纹理化莫尔狄拉克材料提供了局域解析框架，并清晰区分了与真实TBG相关的几何、纹理诱导及输运层面要素。
英文摘要
Slow twist-angle and heterostrain textures in twisted bilayer graphene provide a natural route to phase-space Berry geometry. We show that a purely geometric tetrad/shift sector does not generate mixed Berry curvature once the spin connection is treated consistently. By contrast, a projected textured mini-Dirac cone in twisted bilayer graphene acquires genuine mixed phase-space curvature. We analyze a controlled local Hall-bar limit with a one-dimensional texture and mirror $M_x$. In that limit the pseudogauge gradient renormalizes only the longitudinal conductivity along the textured direction, while a dc nonlinear Hall response appears only when an additional valley-odd tilt generates a Berry-curvature dipole. Both geometric responses peak at the same local filling, $μ_{\rm loc}=\sqrt{2}\,m$, providing a gate-tunable fingerprint of their common origin. All local-cone parameters and their texture susceptibilities are extracted from a heterostrained Bistritzer-MacDonald model at $θ=1.3^\circ$. The tilt invoked in the transport estimates corresponds to heterostrain of only $0.03\%-0.2\%$, below values routinely imaged in devices. The resulting theory provides a local analytic framework for textured moiré Dirac materials and cleanly separates geometric, texture-induced, and transport-level ingredients relevant to realistic TBG.
Comments9 pages + Supplementary material
Journal refPhys. Rev. B 114, 105148 Published 31 August 2026
