Chiappe G, Louis E
Departamento de Física Aplicada, Unidad Asociada del Consejo Superior de Investigaciones Científicas and Instituto Universitario de Materiales, Universidad de Alicante, San Vicente del Raspeig, Alicante 03690, Spain.
Phys Rev Lett. 2006 Aug 18;97(7):076806. doi: 10.1103/PhysRevLett.97.076806.
It has been shown that by distorting a CoPc molecule adsorbed on a Au(111) surface a Kondo effect is induced with a temperature higher than 200 K. We examine a model in which an atom with strong Coulomb repulsion (Co) is surrounded by four atoms on a square (molecule lobes), with two atoms above and below it representing the apex of the STM tip and an atom on the gold surface (all with a single atomic orbital). The Hamiltonian is solved exactly for the isolated cluster, and, after connecting the leads, the conductance is calculated by standard techniques. Quantum interference prevents the existence of the Kondo effect when the orbitals on the square do not interact (undistorted molecule); the Kondo resonance shows up after switching on that interaction. The weight of the Kondo resonance is controlled by the interplay of couplings to the STM tip and the gold surface and between the molecule lobes.
研究表明，通过扭曲吸附在Au(111)表面的CoPc分子，可在高于200 K的温度下诱导出近藤效应。我们研究了一个模型，其中具有强库仑排斥力的原子（Co）被正方形上的四个原子（分子叶瓣）包围，其上方和下方各有两个原子分别代表STM针尖的尖端和金表面的一个原子（均具有单个原子轨道）。对孤立团簇精确求解哈密顿量，连接引线后，通过标准技术计算电导。当正方形上的轨道不相互作用（未扭曲分子）时，量子干涉会阻止近藤效应的存在；开启该相互作用后，近藤共振出现。近藤共振的权重由与STM针尖和金表面的耦合以及分子叶瓣之间的相互作用控制。
