Tkachov G
Institute of Physics, Augsburg University, 86135 Augsburg, Germany. Institute for Theoretical Physics and Astrophysics, University of Wuerzburg, Am Hubland, 97074 Wuerzburg, Germany.
J Phys Condens Matter. 2019 Feb 6;31(5):055301. doi: 10.1088/1361-648X/aaf337. Epub 2018 Nov 23.
In noncentrosymmetric superconductors (NCSs), the conversion of a charge current into spin magnetization-the so called magnetoelectric effect-is the direct indicator of the unconventional, mixed-parity order parameter. This paper proposes a scheme to detect the magnetoelectric effect by anomalous, equal-spin Andreev tunneling in NCS/ferromagnet contacts. The proposal relies on the ability to generate spin-polarized triplet pairing by passing an electric current through an NCS. Such an induced triplet pairing bears a similarity to the paradigmatic nonunitary pairing in triplet superfluids with a complex vector order parameter [Formula: see text]. The qualitative difference is that the induced nonunitary state can be realised in NCSs with a purely real [Formula: see text] by breaking the time-reversal symmetry in current-biased setups. This offers a possibility to access the unconventional superconductivity in NCSs through electrical transport measurements.
在非中心对称超导体(NCSs)中,电荷电流向自旋磁化的转换——即所谓的磁电效应——是非常规混合宇称序参量的直接指标。本文提出了一种通过NCS/铁磁体接触中的反常等自旋安德列夫隧穿来探测磁电效应的方案。该方案依赖于通过NCS施加电流来产生自旋极化三重态配对的能力。这种诱导的三重态配对与具有复矢量序参量[公式:见原文]的三重态超流体中的典型非幺正配对有相似之处。定性的区别在于,通过在电流偏置设置中打破时间反演对称性,可以在具有纯实[公式:见原文]的NCS中实现诱导的非幺正态。这为通过电输运测量来研究NCS中的非常规超导性提供了一种可能性。