# Why only hole conductors can be superconductors

## TL;DR

This paper argues that only hole carriers can become superconductors, challenging conventional theory, and reviews empirical evidence supporting that all superconductors are hole superconductors, with implications for discovering higher critical temperature materials.

## Contribution

It introduces the hypothesis that all superconductors must have hole carriers, providing theoretical reasoning and empirical evidence to support this claim.

## Key findings

- Normal state carriers in superconductors are holes.
- Empirical evidence supports all superconductors are hole superconductors.
- Implications for searching higher $T_c$ superconductors.

## Abstract

The conventional theory of superconductivity says that charge carriers in a metal that becomes superconducting can be either electrons or holes. I argue that this is incorrect. In order to satisfy conservation of mechanical momentum and of entropy of the universe in the superconductor to normal transition in the presence of a magnetic field it is necessary that the normal state charge carriers are holes. I will also review the empirical evidence in favor of the hypothesis that all superconductors are hole superconductors, and discuss the implications of this for the search for higher $T_c$ superconductors.