The flux quantization is a key indication of electron pairing in superconductors. For example, the well-known $h/2e$ flux quantization is considered strong evidence for the existence of charge-$2e$, two-electron Cooper pairs. Here we report evidence for multicharge flux quantization in mesoscopic ring devices fabricated using the transition-metal kagome superconductor ${\mathrm{CsV}}_3{\mathrm{Sb}}_5$. We perform systematic magnetotransport measurements and observe unprecedented quantization of magnetic flux in units of $h/4e$ and $h/6e$ in magnetoresistance oscillations. Specifically, at low temperatures, magnetoresistance oscillations with period $h/2e$ are detected, as expected from the flux quantization for charge-$2e$ superconductivity. We find that the $h/2e$ oscillations are suppressed and replaced by resistance oscillations with $h/4e$ periodicity when the temperature is increased. Increasing the temperature further suppresses the $h/4e$ oscillations, and robust resistance oscillations with $h/6e$ periodicity emerge as evidence for charge-$6e$ flux quantization. Our observations provide the first experimental evidence for the existence of multicharge flux quanta and emergent quantum matter exhibiting higher-charge superconductivity in the strongly fluctuating region above the charge-$2e$ Cooper pair condensate, revealing new insights into the intertwined and vestigial electronic order in kagome superconductors.

中文翻译：

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Kagome 超导环器件中的 Charge- 4e 和 Charge- 6e 通量量子化和更高电荷超导性

通量量子化是超导体中电子配对的关键指标。例如，众所周知的$H/2e$通量量子化被认为是电荷存在的有力证据$2e$，二电子库珀对。在这里，我们报告了使用过渡金属 Kagome 超导体制造的介观环器件中多电荷通量量子化的证据${\mathrm{病毒}}_3{锑}_5$。我们进行系统的磁输运测量，并观察到前所未有的磁通量量子化（以$H/4e$和$H/6e$在磁阻振荡中。具体来说，在低温下，磁阻振荡随周期变化$H/2e$被检测到，正如电荷通量量化所预期的那样$2e$超导。我们发现$H/2e$振荡被抑制并被电阻振荡取代$H/4e$温度升高时的周期性。升高温度进一步抑制$H/4e$振荡和鲁棒电阻振荡$H/6e$周期性出现作为充电的证据-$6e$通量量化。我们的观察提供了第一个实验证据，证明多电荷通量量子的存在和涌现量子物质在电荷上方的强波动区域中表现出更高的电荷超导性。$2e$库珀对凝聚体，揭示了戈薇超导体中相互交织和残留的电子秩序的新见解。