Sharma Rahul, Edkins Stephen D, Wang Zhenyu, Kostin Andrey, Sow Chanchal, Maeno Yoshiteru, Mackenzie Andrew P, Davis J C Séamus, Madhavan Vidya
Laboratory of Atomic and Solid State Physics, Department of Physics, Cornell University, Ithaca, NY 14853.
Condensed Matter Physics and Material Science Department, Brookhaven National Laboratory, Upton, NY 11973.
Proc Natl Acad Sci U S A. 2020 Mar 10;117(10):5222-5227. doi: 10.1073/pnas.1916463117. Epub 2020 Feb 24.
SrRuO has long been the focus of intense research interest because of conjectures that it is a correlated topological superconductor. It is the momentum space (-space) structure of the superconducting energy gap [Formula: see text] on each band that encodes its unknown superconducting order parameter. However, because the energy scales are so low, it has never been possible to directly measure the [Formula: see text] of SrRuO Here, we implement Bogoliubov quasiparticle interference (BQPI) imaging, a technique capable of high-precision measurement of multiband [Formula: see text] At = 90 mK, we visualize a set of Bogoliubov scattering interference wavevectors [Formula: see text] consistent with eight gap nodes/minima that are all closely aligned to the [Formula: see text] crystal lattice directions on both the α and β bands. Taking these observations in combination with other very recent advances in directional thermal conductivity [E. Hassinger , 7, 011032 (2017)], temperature-dependent Knight shift [A. Pustogow , 574, 72-75 (2019)], time-reversal symmetry conservation [S. Kashiwaya , , 100, 094530 (2019)], and theory [A. T. Rømer , 123, 247001 (2019); H. S. Roising, T. Scaffidi, F. Flicker, G. F. Lange, S. H. Simon, 1, 033108 (2019); and O. Gingras, R. Nourafkan, A. S. Tremblay, M. Côté, 123, 217005 (2019)], the BQPI signature of SrRuO appears most consistent with [Formula: see text] having [Formula: see text] [Formula: see text] symmetry.
长期以来，SrRuO一直是深入研究的焦点，因为有推测认为它是一种关联拓扑超导体。每个能带的超导能隙[公式：见正文]的动量空间（-空间）结构编码了其未知的超导序参量。然而，由于能量尺度非常低，从未能够直接测量SrRuO的[公式：见正文]。在此，我们实施了博戈留波夫准粒子干涉（BQPI）成像，这是一种能够高精度测量多能带[公式：见正文]的技术。在温度为90 mK时，我们可视化了一组与八个能隙节点/极小值一致的博戈留波夫散射干涉波矢[公式：见正文]，这些节点/极小值在α和β能带中都与[公式：见正文]晶格方向紧密对齐。将这些观测结果与定向热导率[E. Hassinger，7，011032（2017）]、与温度相关的奈特位移[A. Pustogow，574，72 - 75（2019）]、时间反演对称性守恒[S. Kashiwaya，，100，094530（2019）]以及理论[A. T. Rømer，123，247001（2019）；H. S. Roising，T. Scaffidi，F. Flicker，G. F. Lange，S. H. Simon，1，033108（2019）；以及O. Gingras，R. Nourafkan，A. S. Tremblay，M. Côté，123，217005（2019）]等其他最新进展相结合，SrRuO的BQPI特征似乎最符合[公式：见正文]具有[公式：见正文][公式：见正文]对称性。
