The magnetic-flux quantum (${\Phi }_0$) cannot be generally divided into smaller ones in a usual superconductor. If a subdividing path is present, the science and technology of the superconductor drastically change. In previous studies, we experimentally presented a new, easy way to subdivide ${\Phi }_0$ into smaller quanta (${\Phi }_f$) using an ultrathin Nb bilayer with a through-pinhole (H. Ishizu, H. Yamamori, S. Arisawa, K. Tokiwa, Y. Tanaka, Physica C 595 (2022) 1354029.). However, because of an experimental technical problem, we could not use a higher field to generate more than one ${\Phi }_f$. It was not clear if multiples of ${\Phi }_f$ could be trapped in a pinhole (in a usual superconductor, multiples of ${\Phi }_0$ are trapped in a pinhole). In this study, we observed multiple fractional phase shifts with a direct-current superconducting interference device (SQUID) placed on an ultrathin Nb bilayer disk containing a through-pinhole using an improved modification of an experimental procedure. The phase shift for the SQUID with the bilayer disk is an integer multiple of a basic fractional phase shift divided by 2π. However, we did not observe the fractional phase shift for a SQUID with a single-layer disk. These observations indicate that multiple fractional flux quanta are trapped in the bilayer disk. According to the vortex-molecule model, if the vortex molecule is larger than the bilayer disk, such quanta can be trapped. This is one example of altering a fundamental (universal) physical constant. The SQUID can more sensitively detect ${\Phi }_f$ than ${\Phi }_0$, rendering the design of novel superconducting electronics possible.

磁通量量子 (${\Phi }_0$) 在通常的超导体中通常不能分成更小的部分。如果存在细分路径，超导体的科学和技术将发生巨大变化。在之前的研究中，我们通过实验提出了一种新的、简单的细分方法${\Phi }_0$变成更小的量子（${\Phi }_F$) 使用具有通孔的超薄铌双层 (H. Ishizu, H. Yamamori, S. Arisawa, K. Tokiwa, Y. Tanaka, Physica C 595 (2022) 1354029.)。但是，由于实验技术问题，我们无法使用更高的场生成多个${\Phi }_F$. 目前尚不清楚是否为倍数${\Phi }_F$可能会被困在针孔中（在通常的超导体中，${\Phi }_0$被困在针孔中）。在这项研究中，我们使用改进的实验程序改进了将直流超导干涉装置 (SQUID) 放置在包含通孔的超薄 Nb 双层盘上，观察到多个分数相移。具有双层盘的 SQUID 的相移是基本分数相移除以 2π 的整数倍。然而，我们没有观察到具有单层磁盘的 SQUID 的分数相移。这些观察表明多个分数通量量子被困在双层盘中。根据涡旋分子模型，如果涡旋分子大于双层盘，则可以捕获这样的量子。这是改变基本（通用）物理常数的一个例子。SQUID 可以更灵敏地检测${\Phi }_F$比${\Phi }_0$，使新型超导电子器件的设计成为可能。