论文标题：Orbital-selective spin excitation of a magnetic porphyrin

期刊：Communications Physics

作者：Jose Ignacio Pascual et al

发表时间：2018/05/03

数字识别码：10.1038/s42005-018-0015-6

原文链接：https://www.nature.com/articles/s42005-018-0015-6?utm_source=Other_website&utm_medium=Website_links&utm_content=RenLi-Nature-Communications_Physics-Physics_of_Condensed_Matter-China&utm_campaign=NEWCOMMS_USG_JRCN_RL_sciencenet_spin_Aug_3rd

近日《通讯-物理学》发表的一项研究Orbital-selective spin excitation of a magnetic porphyrin 展示了可以通过向两个不同的轨道通道注入电子的方式来实现分子自旋的选择性激发。

局域自旋所导致的电子散射是实现检测和控制自旋掺杂物质磁性状态的最终过程。在分子尺度下，散射是通过自旋所在的轨道调节的。来自西班牙CIC nanoGUNE研究中心的Jose Ignacio Pascual及其研究团队，报道了通过不同分子轨道的隧穿实现了分子自旋的选择性激发。他们通过铁卟啉的空间分辨隧道谱分析，揭示了非弹性自旋激发延伸到了铁位点之外，并沿着分子改变形状和对称性。进一步，将密度泛函辅助理论模拟与散射现象学模型相结合，他们证明了非弹性信号的扩展和谱线形状是由于不同前线轨道所辅助的激发途径造成的。最后，通过选择电子注入分子内部的位点，对隧穿过程中铁和吡咯轨道的相对权重进行了修正。因此，他们发现由光谱线形状所反映出的激发机制，取决于所选分子轨道的局域化和能量校准的程度。

摘要：Scattering of electrons by localized spins is the ultimate process enabling detection and control of the magnetic state of a spin-doped material. At the molecular scale, scattering is mediated by the orbitals hosting the spin. Here we report the selective excitation of a molecular spin by tunneling through different molecular orbitals. Spatially resolved tunneling spectra on iron-porphyrins reveal that the inelastic spin excitation extends beyond the iron site, changing shape and symmetry along the molecule. Combining density functional theory simulations with a phenomenological scattering model, we show that the extension and lineshape of the inelastic signal are due to excitation pathways assisted by different frontier orbitals. By selecting the intramolecular site for electron injection, the relative weight of iron and pyrrole orbitals in the tunneling process is modified. Thus, the excitation mechanism, reflected by its spectral lineshape, depends on the degree of localization and energy alignment of the chosen molecular orbital.

阅读论文全文请访问：https://www.nature.com/articles/s42005-018-0015-6?utm_source=Other_website&utm_medium=Website_links&utm_content=RenLi-Nature-Communications_Physics-Physics_of_Condensed_Matter-China&utm_campaign=NEWCOMMS_USG_JRCN_RL_sciencenet_spin_Aug_3rd

期刊介绍：Communications Physics is an open access journal from Nature Research publishing high-quality research, reviews and commentary in all areas of physics. Research papers published by the journal represent significant advances bringing new insight to a specialized area of research.

（来源：科学网）