标题： 揭示RbV$_3$Sb$_5$中电子跃迁的性质 与避免能级交叉 $μ$SR 显示英文标题

标题： Unveiling the nature of electronic transitions in RbV$_3$Sb$_5$ with Avoided Level Crossing $μ$SR

摘要： Kagome超导体AV$_{3}$Sb$_{5}$为研究多种电子序之间的相互作用提供了一个独特的平台，包括超导性、电荷密度波、向列相等。 理解从电荷密度波到超导转变的电子态演化对于揭示导致这些非磁性金属异常磁性的电荷、自旋和晶格自由度之间的相互作用至关重要。 先前的零场和高场$\mu$SR研究揭示了μ子自旋弛豫率中的两个异常，第一个变化发生在$T_{CDW} \sim 100$ K，第二个急剧增加发生在$T^{*}\sim 40$ K，在施加磁场下进一步增强，从而表明存在磁性起源的贡献。 在本研究中，我们使用避免能级交叉$\mu$SR技术来研究近零外加场中的电荷序。 通过跟踪四极矩能级交叉共振的温度依赖性，我们研究了kagome平面上V核的电场梯度的演化。 我们的结果表明，电荷密度在$T^{*}$处开始发生显著重排，表明电荷分布出现转变，可能是电子起源的，发生在$T_{CDW}$以下。 这些发现结合之前的$\mu$SR、STM 和 NMR 研究，强调了这些系统中邻近相的紧密交织特性，其中电荷重排主导了在$T^{*}$以下$\mu$SR 衰减率的进一步增加。 显示英文摘要

摘要： Kagome superconductors AV$_{3}$Sb$_{5}$ provide a unique platform for studying the interplay between a variety of electronic orders, including superconductivity, charge density waves, nematic phases and more. Understanding the evolution of the electronic state from the charge density wave to the superconducting transition is essential for unraveling the interplay of charge, spin, and lattice degrees of freedom giving rise to the unusual magnetic properties of these nonmagnetic metals. Previous zero-field and high-field $\mu$SR studies revealed two anomalies in the muon spin relaxation rate, a first change at $T_{CDW} \sim 100$ K and a second steep increase at $T^{*}\sim 40$ K, further enhanced by an applied magnetic field, thus suggesting a contribution of magnetic origin. In this study, we use the avoided level crossing $\mu$SR technique to investigate charge order in near-zero applied field. By tracking the temperature dependence of quadrupolar level-crossing resonances, we examined the evolution of the electric field gradient at V nuclei in the kagome plane. Our results show a significant rearrangement of the charge density starting at $T^{*}$ indicating a transition in the charge distribution, likely electronic in origin, well below $T_{CDW}$. These findings, combined with previous $\mu$SR, STM, and NMR studies, emphasize the intertwined nature of proximate phases in these systems, with the charge rearrangement dominating the additional increase in $\mu$SR relaxation rate below $T^{*}$.