Pt|铁氧体|铜酸盐超导三明治薄膜中的振荡 Nernst 效应。

Oscillatory Nernst effect in Pt|ferrite|cuprate-superconductor trilayer films.

机构信息

Institute for Materials Research, Tohoku University, Sendai, 980-8577, Japan.

Spin Quantum Rectification Project, ERATO, Japan Science and Technology Agency, Aoba-ku, Sendai, 980-8577, Japan.

出版信息

Sci Rep. 2017 Jul 13;7(1):5358. doi: 10.1038/s41598-017-05747-6.

DOI:10.1038/s41598-017-05747-6

PMID:28706217

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC5509755/

Abstract

Although magnetism and superconductivity hardly coexist in a single material, recent advances in nanotechnology and spintronics have brought to light their interplay in magnetotransport in thin-film heterostructures. Here, we found a periodic oscillation of Nernst voltage with respect to magnetic fields in Pt|LiFeO (Pt|LFO) bilayers grown on a cuprate superconductor YBaCuO (YBCO). At high temperatures above the superconducting transition temperature (T ) of YBCO, spin Seebeck voltages originating in Pt|LFO layers are observed. As temperature decreases well below T , the spin Seebeck voltage is suppressed and unconventional periodic voltage oscillation as a function of magnetic fields appears; such an oscillation emerging along the Hall direction in the superconducting state has not been observed yet. Dynamics of superconducting vortices pinned by surface precipitates seems responsible for the oscillatory Nernst effect.

摘要

虽然单个材料中很难同时存在磁性和超导性，但纳米技术和自旋电子学的最新进展揭示了它们在薄膜异质结构中的磁输运中的相互作用。在这里，我们在在铜酸盐超导体 YBaCuO（YBCO）上生长的 Pt|LiFeO（Pt|LFO）双层膜中发现了 Nernst 电压相对于磁场的周期性振荡。在高于 YBCO 超导转变温度（T）的高温下，观察到源于 Pt|LFO 层的自旋塞贝克电压。当温度远低于 T 时，自旋塞贝克电压被抑制，并且出现了作为磁场函数的非传统周期性电压振荡；在超导状态下，沿 Hall 方向出现的这种振荡尚未被观察到。由表面沉淀物钉扎的超导涡旋的动力学似乎是产生振荡 Nernst 效应的原因。