# An observable prerequisite for the existence of persistent currents

## TL;DR

This paper presents a classical model suggesting that persistent currents in superconductors are thermodynamically necessary, as their decay would violate the second law of thermodynamics, supported by theoretical analysis and proposed experiments.

## Contribution

It introduces a classical explanation for persistent currents, linking their existence to thermodynamic principles and proposing experimental validation.

## Key findings

- Joule effect causes temperature decrease in superconductors
- Persistent currents are thermodynamically justified
- Proposed experiment to test the model in type I and II superconductors

## Abstract

A classical model is presented for persistent currents in superconductors. Their existence is argued to be warranted because their decay would violate the second law of thermodynamics. This conclusion is achieved by analyzing comparatively Ohm's law and the Joule effect in normal metals and superconducting materials. Whereas Ohm's law applies in identical terms in both cases, the Joule effect is shown to cause the temperature of a superconducting sample to \textit{decrease}. An experiment is proposed to check the validity of this work in superconductors of both types I and II.