Controlled Modification of Superconductivity in Epitaxial Atomic Layer-Organic Molecule Heterostructures
Controlled Modification of Superconductivity in Epitaxial Atomic Layer-Organic Molecule Heterostructures
复制标题
外延原子层-有机分子异质结构中超导性的可控修饰
DOI：
10.1021/acs.nanolett.6b05010
复制
发表时间：
2017
期刊：
影响因子：
10.8
通讯作者：
and T. Uchihashi
中科院分区：
文献类型：
--
作者：
S. Yoshizawa;E. Minamitani;S. Vijayaraghavan;P. Mishra;Y. Takagi;T. Yokoyama;H. Oba;J. Nitta;K. Sakamoto;S. Watanabe;T. Nakayama;and T. Uchihashi
自组装的有机分子可能是二维原子层超导体的一个很好的电荷和自旋来源。在这里，我们调查2D异质结的基础上，在原子层外延生长在Si和高度有序的金属酞菁（MPc，M = Mn，Cu）通过各种技术：扫描隧道显微镜，电子输运测量，角分辨光电子能谱，X射线磁性圆二色性，从头计算。我们证明了异质结构的超导转变温度（Tc）可以以可控的方式进行修改。特别地，从Mn到Cu的配位金属原子的取代被发现逆转Tc从负到正的方向移动。这种独特的行为归因于电荷和自旋效应的竞争，后者由相关d轨道的方向性决定。本研究表明，分子诱导的表面掺杂的有效性和微观理解这些二维异质结构中的分子状态的意义。
Self-assembled organic molecules can potentially be an excellent source of charge and spin for two-dimensional (2D) atomic-layer superconductors. Here we investigate 2D heterostructures based on In atomic layers epitaxially grown on Si and highly ordered metal-phthalocyanine (MPc, M = Mn, Cu) through a variety of techniques: scanning tunneling microscopy, electron transport measurements, angle-resolved photoemission spectroscopy, X-ray magnetic circular dichroism, and ab initio calculations. We demonstrate that the superconducting transition temperature (Tc) of the heterostructures can be modified in a controllable manner. Particularly, the substitution of the coordinated metal atoms from Mn to Cu is found to reverse theTcshift from negative to positive directions. This distinctive behavior is attributed to a competition of charge and spin effects, the latter of which is governed by the directionality of the relevant d-orbitals. The present study shows the effectiveness of molecule-induced surface doping and the significance of microscopic understanding of the molecular states in these 2D heterostructures.