Abstract Geometric phase is a fundamental concept which emerges in various systems, regardless of quantum or classical description. Here, we experimentally demonstrate that the geometric phase can also emerge in a macroscopic thermal convection-conduction system. Following Li et al. [Science 364 (2019) 170–173], we study two moving rings with equal-but-opposite velocities, joined together by a stationary intermediate layer. We firstly confirm an exceptional point of velocity which separates a stationary temperature profile and a moving one. We then investigate a cyclic path of time-varying velocity containing the exceptional point, and an extra phase difference of π appears (say, the geometric phase). We finally reveal the mechanism of effective conductivity enhancement, which helps design an invisibility cloak. These results broaden the scope of geometric phase and effective conductivity enhancement, which have potential applications in thermal management.

中文翻译：

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热对流传导中的几何相、有效的电导率增强和隐形斗篷

摘要 几何相位是出现在各种系统中的基本概念，无论是量子描述还是经典描述。在这里，我们通过实验证明几何相位也可以出现在宏观热对流传导系统中。继李等人。[Science 364 (2019) 170–173]，我们研究了两个速度相等但速度相反的运动环，它们由一个静止的中间层连接在一起。我们首先确认了一个特殊的速度点，它将静止的温度曲线和移动的温度曲线分开。然后，我们研究包含异常点的时变速度的循环路径，并出现 π 的额外相位差（例如，几何相位）。我们最终揭示了有效增强导电性的机制，这有助于设计隐形斗篷。