Fridman Nofar, Feld Tomer Daniel, Noah Avia, Zalic Ayelet, Markman Maya, Devidas T R, Zur Yishay, Grynszpan Einav, Gutfreund Alon, Keren Itai, Vakahi Atzmon, Remennik Sergei, Watanabe Kenji, Taniguchi Takashi, Huber Martin Emile, Aleiner Igor, Steinberg Hadar, Agam Oded, Anahory Yonathan
The Racah Institute of Physics, The Hebrew University, Jerusalem, Israel.
Center for Nanoscience and Nanotechnology, Hebrew University of Jerusalem, Jerusalem, Israel.
Nat Commun. 2025 Mar 31;16(1):2696. doi: 10.1038/s41467-025-57817-3.
The coexistence of multiple types of orders is a common thread in condensed matter physics and unconventional superconductors. The nature of superconducting orders may be unveiled by analyzing local perturbations such as vortices. For thin films, the vortex magnetic profile is characterized by the Pearl-length , which is inversely proportional to the 2D superfluid density; hence, normally, also inversely proportional to the film thickness, . Here we employ the scanning SQUID-on-tip microscopy to measure in NbSe flakes with thicknesses ranging from to layers. For , we find the expected dependence . However, six-layer films show a sharp increase of deviating by a factor of three from the expected value. This value remains fixed for to . This unexpected behavior suggests the competition between two orders; one residing only on the first and last layers of the film while the other prevails in all layers.
多种序的共存是凝聚态物理和非常规超导体中的一个共同主题。超导序的本质可以通过分析诸如涡旋等局部微扰来揭示。对于薄膜，涡旋磁分布由珀尔长度来表征，它与二维超流密度成反比；因此，通常也与薄膜厚度(d)成反比。在这里，我们使用扫描式针尖超导量子干涉显微镜来测量厚度在(1)到(6)层范围内的(NbSe)薄片中的珀尔长度。对于(1)到(5)层，我们发现了预期的依赖关系。然而，六层薄膜显示出珀尔长度急剧增加，偏离预期值达三倍之多。对于(7)到(10)层，这个值保持不变。这种意外行为表明两种序之间存在竞争；一种仅存在于薄膜的第一层和最后一层，而另一种在所有层中占主导。
