发表机构
University of California, Berkeley; Lawrence Berkeley National Laboratory（加州大学伯克利分校; 劳伦斯伯克利国家实验室）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究通过4D-STEM定量表征了模板生长碲量子线中的介观尺度晶体学手性，发现扭转与应变和线宽相关，结合第一性原理计算提出应变偏置的扭转弛豫机制，为工程手性晶格态提供新途径。
AI 中文摘要
螺旋序可以促进晶体材料中的对称性破缺和涌现物理响应，然而内在手性如何在原子长度尺度之外表现仍知之甚少。本文报道了在非晶衬底上模板生长的碲（Te）量子线中长程晶体学手性的直接观察和定量表征。四维扫描透射电子显微镜（4D-STEM）能够以纳米级空间分辨率对晶体取向进行定量映射。由此产生的取向图确立了连续的介观尺度晶格扭转，为长程晶体学手性提供了直接证据。相关的取向和应变映射揭示了显著的横向应变异质性，其中压缩应变集中在线的内部。对多根线的系统分析表明，较高的扭转率通常与较弱的横向压缩应变、较窄的线以及更好的原子链-模板轴对齐相关。对有限Te纳米棒的补充第一性原理计算进一步表明，扭转在核尺度的Te团簇中本质上是可及的，并且应变可以偏向优选的扭转状态。总之，这些结果支持一种生长掺入、应变偏置的图景，其中纳米尺度限制和各向异性应变促进扭转弛豫并稳定Te纳米结构中的介观尺度手性，突出了应变和限制作为在范德华纳米结构中工程手性晶格态的潜在途径。
英文摘要
Helical order can facilitate symmetry breaking and emergent physical responses in crystalline materials, yet how intrinsic chirality manifests beyond atomic length scales remains poorly understood. Here, the direct observation and quantitative characterization of long-range crystallographic helicity in template-grown tellurium (Te) quantum wires on amorphous substrates are reported. Four-dimensional scanning transmission electron microscopy (4D-STEM) enables quantitative mapping of crystallographic orientation with nanometer-scale spatial resolution. The resulting orientation maps establish continuous mesoscale lattice twisting, providing direct evidence of long-range crystallographic helicity. Correlated orientation and strain mapping reveal pronounced lateral strain heterogeneity, with compressive strain concentrated within the wire interior. Systematic analysis across multiple wires suggests that higher twist rates are generally associated with weaker lateral compressive strain, narrower wires, and better atomic chain - template axis alignment. Complementary first-principles calculations on finite Te nanorods further suggest that twisting is intrinsically accessible in nucleus-scale Te clusters and strain can bias the preferred torsional state. Together, these results support a growth-incorporated, strain-biased picture in which nanoscale confinement and anisotropic strain facilitate torsional relaxation and stabilize mesoscale helicity in Te nanostructures highlighting strain and confinement as potential routes for engineering chiral lattice states in van der Waals nanostructures.
Comments42 pages, 5 figures, 10 supplementary figures
