Cooper pairs as bosons

TL;DR

This paper demonstrates that Cooper pairs, despite their differences from BCS pairs, obey Bose-Einstein statistics and can undergo Bose-Einstein condensation, providing a new perspective on superconductivity and superfluidity.

Contribution

It shows that Cooper pairs obey Bose-Einstein statistics and can condense, challenging the common belief that they do not.

Findings

Cooper pairs obey Bose-Einstein statistics.

CPs can undergo Bose-Einstein condensation.

Implications for superconductivity and superfluidity.

Abstract

Although BCS pairs of fermions are known not to obey Bose-Einstein (BE) commutation relations nor BE statistics, we show how Cooper pairs (CPs), whether the simple original ones or the CPs recently generalized in a many-body Bethe-Salpeter approach, being clearly distinct from BCS pairs at least obey BE statistics. Hence, contrary to widespread popular belief, CPs can undergo BE condensation to account for superconductivity if charged, as well as for neutral-atom fermion superfluidity where CPs, but uncharged, are also expected to form.