Geometric phase, effective conductivity enhancement, and invisibility cloak in thermal convection-conduction

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 pi 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. (C) 2020 Elsevier Ltd. All rights reserved.

Automated summary

Geometric phase, a fundamental concept in both quantum and classical systems, has been experimentally demonstrated in a macroscopic thermal convection-conduction system. The results broaden the scope of geometric phase applications in the field of thermal management, showing potential for effective conductivity enhancement.