Garnier Léo, Verlhac Benjamin, Abufager Paula, Lorente Nicolás, Ormaza Maider, Limot Laurent
Université de Strasbourg, CNRS, IPCMS, UMR 7504, Strasbourg F-67000, France.
Instituto de Física de Rosario, Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) and Universidad Nacional de Rosario, Avenida Pellegrini 250 (2000), Rosario 2000, Argentina.
Nano Lett. 2020 Nov 11;20(11):8193-8199. doi: 10.1021/acs.nanolett.0c03271. Epub 2020 Oct 29.
A single molecule offers to tailor and control the probing capability of a scanning tunneling microscope when placed on the tip. With the help of first-principles calculations, we show that on-tip spin sensitivity is possible through the Kondo ground state of a spin = 1/2 cobaltocene molecule. When attached to the tip apex, we observe a reproducible Kondo resonance, which splits apart upon tuning the exchange coupling of cobaltocene to an iron atom on the surface. The spin-split Kondo resonance provides quantitative information on the exchange field and on the spin polarization of the iron atom. We also demonstrate that molecular vibrations cause the emergence of Kondo side peaks, which, unlike the Kondo resonance, are sensitive to cobaltocene adsorption.
当一个单分子置于扫描隧道显微镜的针尖上时，它能够对该显微镜的探测能力进行定制和控制。借助第一性原理计算，我们表明通过自旋为1/2的二茂钴分子的近藤基态可以实现针尖上的自旋敏感性。当连接到针尖顶端时，我们观察到一个可重复的近藤共振，在调节二茂钴与表面铁原子的交换耦合时，该共振会分裂。自旋分裂的近藤共振提供了关于交换场和铁原子自旋极化的定量信息。我们还证明分子振动会导致近藤边峰的出现，与近藤共振不同，这些边峰对二茂钴的吸附敏感。
