Influence of Magnetic Ordering between Cr Adatoms on the Yu-Shiba-Rusinov States of the β-Bi2Pd Superconductor
Influence of Magnetic Ordering between Cr Adatoms on the Yu-Shiba-Rusinov States of the β-Bi2Pd Superconductor
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DOI：
10.1103/physrevlett.120.167001
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发表时间：
2018-04-18
影响因子：
8.6
通讯作者：
Lorente, Nicolas
中科院分区：
文献类型：
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作者：
Choi, Deung-Jang;Garcia Fernandez, Carlos;Lorente, Nicolas
我们证明了超导体上耦合原子二聚体的磁有序是由它们的谱内特征揭示的。超导体β - bi2pd表面的铬原子显示出Yu-Shiba-Rusinov束缚态，在隧穿光谱中以俘获内激发对的形式被探测到。通过扫描隧道显微镜尖端的原子操纵，我们形成了不同排列的铬二聚体，并发现它们的内部特征相对于单个原子出现移位或分裂。这些光谱变化与二聚体的磁耦合有关，铁磁性或反铁磁性，密度泛函理论模拟证实了这一点。观察到的隧穿光谱之间显著的质性差异证明了在原子尺度上，片内柴巴态对磁有序极为敏感。
We show that the magnetic ordering of coupled atomic dimers on a superconductor is revealed by their intragap spectral features. Chromium atoms on the superconductor beta-Bi2Pd surface display Yu-Shiba-Rusinov bound states, detected as pairs of intragap excitations in tunneling spectra. By means of atomic manipulation with a scanning tunneling microscope's tip, we form Cr dimers with different arrangements and find that their intragap features appear either shifted or split with respect to single atoms. These spectral variations are associated with the magnetic coupling, ferromagnetic or antiferromagnetic, of the dimer, as confirmed by density functional theory simulations. The striking qualitative differences between the observed tunneling spectra prove that intragap Shiba states are extremely sensitive to the magnetic ordering on the atomic scale.