Minowa Yosuke, Aoyagi Shota, Inui Sosuke, Nakagawa Tomo, Asaka Gamu, Tsubota Makoto, Ashida Masaaki
Graduate School of Engineering Science, Osaka University, 1-3, Machikane-yama, Toyonaka, Osaka, Japan.
JST, PRESTO, 4-1-8 Honcho, Kawaguchi, Saitama, Japan.
Sci Adv. 2022 May 6;8(18):eabn1143. doi: 10.1126/sciadv.abn1143. Epub 2022 May 4.
Impurity injection into superfluid helium is a simple and appealing method with diverse applications, including high-precision spectroscopy, quantum computing with surface electrons, nano/micromaterial synthesis, and flow visualization. Quantized vortices play a major role in the interaction between superfluid helium and light impurities. However, the basic principle governing this interaction is still unclear for dense (high mass density and refractive index) materials, such as semiconductor and metal impurities. Here, we provide experimental evidence of the dense silicon nanoparticle attraction to the quantized vortex cores. We prepared the silicon nanoparticles via in situ laser ablation. Following laser ablation, we observed that the silicon nanoparticles formed curved filament-like structures, indicative of quantized vortex cores. We also observed that two accidentally intersecting quantized vortices exchanged their parts, a phenomenon called quantized vortex reconnection. This behavior closely matches the dynamical scaling of reconnections. Our results provide a previously unexplored method for visualizing and studying impurity-quantized vortex interactions.
向超流氦中注入杂质是一种简单且有吸引力的方法，具有多种应用，包括高精度光谱学、表面电子量子计算、纳米/微材料合成以及流动可视化。量子涡旋在超流氦与轻杂质的相互作用中起主要作用。然而，对于诸如半导体和金属杂质等致密（高质量密度和折射率）材料，这种相互作用的基本原理仍不清楚。在此，我们提供了致密硅纳米颗粒被量子涡旋核吸引的实验证据。我们通过原位激光烧蚀制备了硅纳米颗粒。激光烧蚀后，我们观察到硅纳米颗粒形成了弯曲的丝状结构，这表明存在量子涡旋核。我们还观察到两个意外相交的量子涡旋交换了它们的部分，这种现象称为量子涡旋重新连接。这种行为与重新连接的动力学标度密切匹配。我们的结果提供了一种以前未探索过的可视化和研究杂质 - 量子涡旋相互作用的方法。
