School of Physics and State Key Laboratory of Crystal Materials, Shandong University , Jinan, Shandong 250100, China.
Department of Materials Science and Engineering, University of Utah , Salt Lake City, Utah 84112, United States.
Nano Lett. 2017 Oct 11;17(10):6166-6170. doi: 10.1021/acs.nanolett.7b02795. Epub 2017 Sep 15.
Superconductivity is a fascinating quantum phenomenon characterized by zero electrical resistance and the Meissner effect. To date, several distinct families of superconductors (SCs) have been discovered. These include three-dimensional (3D) bulk SCs in both inorganic and organic materials as well as two-dimensional (2D) thin film SCs but only in inorganic materials. Here we predict superconductivity in 2D and 3D organic metal-organic frameworks by using first-principles calculations. We show that the highly conductive and recently synthesized Cu-benzenehexathial (BHT) is a Bardeen-Cooper-Schrieffer SC. Remarkably, the monolayer Cu-BHT has a critical temperature (T) of 4.43 K, while T of bulk Cu-BHT is 1.58 K. Different from the enhanced T in 2D inorganic SCs which is induced by interfacial effects, the T enhancement in this 2D organic SC is revealed to be the out-of-plane soft-mode vibrations, analogous to surface mode enhancement originally proposed by Ginzburg. Our findings not only shed new light on better understanding 2D superconductivity but also open a new direction to search for SCs by interface engineering with organic materials.
超导性是一种迷人的量子现象，其特征为零电阻和迈斯纳效应。迄今为止，已经发现了几类不同的超导体（SCs）。这些超导体包括无机和有机材料中的三维（3D）体 SCs 以及二维（2D）薄膜 SCs，但仅在无机材料中存在。在这里，我们通过第一性原理计算预测了 2D 和 3D 有机金属-有机骨架中的超导性。我们表明，高导电性且最近合成的 Cu-苯六硫（BHT）是 Bardeen-Cooper-Schrieffer SC。值得注意的是，单层 Cu-BHT 的临界温度（T）为 4.43 K，而块状 Cu-BHT 的 T 为 1.58 K。与由界面效应引起的 2D 无机 SCs 中增强 T 的情况不同，在这种 2D 有机 SC 中，T 的增强被揭示为面外软模振动，类似于最初由 Ginzburg 提出的表面模式增强。我们的发现不仅为更好地理解 2D 超导性提供了新的视角，而且为通过与有机材料的界面工程来寻找 SCs 开辟了新的方向。
