Reverse heat flow with Peltier-induced thermoinductive effect

TL;DR

This paper introduces a controllable reverse heat flow phenomenon in solid materials, enabled by thermal inertia and ac current, akin to a thermoinductive effect, with potential applications in thermal circuit design.

Contribution

It presents the concept of a thermoinductive effect induced by the Peltier effect, providing an exact solution and experimental demonstration of reverse heat flow in solid-state systems.

Findings

Reverse heat flow occurs universally in solid-state systems.

Thermoelectric properties significantly enhance the effect.

Local cooling of 25 mK achieved in (Bi,Sb)2Te3.

Abstract

The concept of "thermal inductance" expands the options of thermal circuit design. However, the inductive component is the only missing components in thermal circuits, unlike their electromagnetic counterparts. Herein, we report an electrically controllable reverse heat flow, in which heat flows from a low-temperature side to a high-temperature side locally and temporarily in a single material by imposing thermal inertia and an ac current. This effect can be regarded as an equivalent of the "thermoinductive" effect induced by the Peltier effect. We derive an exact solution indicating that this reverse heat flow occurs universally in solid-state systems and that it is considerably enhanced by thermoelectric properties. A local cooling of 25 mK is demonstrated in (Bi,Sb)2Te3, which is explained by our exact solution. This effect can be directly applied to the potential fabrication of a "thermoinductor" in thermal circuits.