Kondo Effect in a Neutral and Stable All Organic Radical Single Molecule Break Junction
Kondo Effect in a Neutral and Stable All Organic Radical Single Molecule Break Junction
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DOI：
10.1021/acs.nanolett.5b00155
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发表时间：
2015-05-01
期刊：
影响因子：
10.8
通讯作者：
van der Zant, Herre S. J.
中科院分区：
文献类型：
--
作者：
Frisenda, Riccardo;Gaudenzi, Rocco;van der Zant, Herre S. J.
有机自由基是中性的纯有机分子，由于分子在基态中存在不成对的电子而表现出固有的磁矩。这种性质，加上低自旋轨道耦合和弱超精细相互作用，使中性有机自由基成为分子自旋电子学的良好候选者，只要自由基性质在固态电子器件中是稳定的。在这里，我们证明了多氯三苯基甲基自由基分子的顺磁性以Kondo异常的形式在二端和三端固态器件中保持不变，无论机械和静电变化如何。事实上，我们的研究结果表明，在电极位移和静电环境的变化下，近藤异常是稳健的，这表明自由基中的局部轨道是磁性的来源。密度泛函计算和相应非自由基的测量结果有力地支持了这一观点。这些结果为在自旋电子学设备中使用全有机中性自由基分子铺平了道路，并为进一步研究近藤物理学打开了大门。
Organic radicals are neutral, purely organic molecules exhibiting an intrinsic magnetic moment due to the presence of an unpaired electron in the molecule in its ground state. This property, added to the low spin-orbit coupling and weak hyperfine interactions, make neutral organic radicals good candidates for molecular spintronics insofar as the radical character is stable in solid state electronic devices. Here we show that the paramagnetism of the polychlorotriphenylmethyl radical molecule in the form of a Kondo anomaly is preserved in two- and three-terminal solid-state devices, regardless of mechanical and electrostatic changes. Indeed, our results demonstrate that the Kondo anomaly is robust under electrodes displacement and changes of the electrostatic environment, pointing to a localized orbital in the radical as the source of magnetism. Strong support to this picture is provided by density functional calculations and measurements of the corresponding nonradical species. These results pave the way toward the use of all-organic neutral radical molecules in spintronics devices and open the door to further investigations into Kondo physics.