Three-dimensional networks of superconducting NbSe2 flakes with nearly isotropic large upper critical field
Three-dimensional networks of superconducting NbSe2 flakes with nearly isotropic large upper critical field
复制标题
DOI：
10.1038/s41699-021-00210-7
复制
发表时间：
2021-03
影响因子：
9.7
通讯作者：
Togo Takahashi;Chisato Ando;M. Saito;Y. Miyata;Y. Nakanishi;J. Pu;T. Takenobu
中科院分区：
文献类型：
--
作者：
Togo Takahashi;Chisato Ando;M. Saito;Y. Miyata;Y. Nakanishi;J. Pu;T. Takenobu
增加超导体的上临界场Hc2In是超导应用中最重要的要求之一。二维非中心对称的NbSe2是一个很有前途的候选者，因为它的对断裂受到自旋动量锁定效应的保护，导致了巨大的面内Hc2(~50 T)。然而，2DNbSe2的强各向异性抑制了面外Hc2(<；5 T)的稳健性。为了解决这个问题，我们提出了一种合成方法来制备具有接近各向同性的大Hc2的NbSe2超导薄膜。可扩展的硒化方法是为创建3D超导网络而量身定做的，其中2D NbSe2薄片垂直对准衬底。角分辨的磁输运表明，在外加磁场作用下，任意方向的Hc2值都超过了20 T。Hc2的各向同性归因于NbSe2通过3D结构薄膜的本征各向异性的平均化，这是由X射线衍射测量确定的。提出的合成方法将提供一种新的方法来创造实用的超导体，这种超导体对磁场具有很强的抵抗力。
Increasing the upper critical fieldHc2in superconductors is one of the most significant requirements for superconducting applications. Two-dimensional (2D) noncentrosymmetric NbSe2is a promising candidate because its pair breaking is protected by the spin-momentum locking effect, resulting in a giant in-planeHc2(~50 T). However, the strong anisotropy of 2D NbSe2suppresses the robustness of out-of-planeHc2(<5 T). To overcome this issue, we propose a synthetic approach to produce superconducting NbSe2films with a nearly isotropic largeHc2. Scalable selenization methods are tailored to create 3D superconducting networks in which 2D NbSe2flakes are vertically aligned to the substrates. The angle-resolved magneto-transports reveal enhancedHc2values that exceed 20 T for arbitrary directions under externally applied magnetic fields. The isotropic nature ofHc2is attributed to the averaging intrinsic anisotropy of NbSe2through 3D structured films, which was determined by X-ray diffraction measurements. The proposed synthetic approach will provide a new method for creating practical superconductors that are robust against magnetic fields.