A chemically driven quantum phase transition in a two-molecule Kondo system
A chemically driven quantum phase transition in a two-molecule Kondo system
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DOI：
10.1038/nphys3737
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发表时间：
2016-09-01
期刊：
影响因子：
19.6
通讯作者：
Tautz, F. Stefan
中科院分区：
文献类型：
--
作者：
Esat, Taner;Lechtenberg, Benedikt;Tautz, F. Stefan
由少量原子或分子组成的纳米结构的磁性通常由磁交换相互作用决定。在这里，我们表明，非磁性，化学相互作用可以有一个类似的决定性影响，如果自旋携带的轨道在空间中延伸，因此允许直接耦合的磁性波函数重叠和形成成键和反键轨道。我们证明了这是一个二聚体的金属分子络合物的Au（111）表面。两个单体之间的波函数重叠的变化驱动表面吸附的二聚体通过量子相变从欠屏蔽三重态到单重态基态，其中一个配置位于非常接近量子临界点。
The magnetic properties of nanostructures that consist of a small number of atoms or molecules are typically determined by magnetic exchange interactions. Here, we show that non-magnetic, chemical interactions can have a similarly decisive effect if spin-moment-carrying orbitals extend in space and therefore allow the direct coupling of magnetic properties to wavefunction overlap and the formation of bonding and antibonding orbitals. We demonstrate this for a dimer of metal-molecule complexes on the Au(111) surface. A changing wavefunction overlap between the two monomers drives the surface-adsorbed dimer through a quantum phase transition from an underscreened triplet to a singlet ground state, with one configuration being located extremely close to a quantum critical point.