Magnon-mediated Binding between Holes in an Antiferromagnet

TL;DR

This paper investigates how magnon exchange mediates long-range attractive forces between holes in an antiferromagnet, leading to bound states with d-wave symmetry that could relate to high-temperature superconductivity.

Contribution

It provides a theoretical analysis of magnon-mediated interactions between holes, revealing the potential for bound states with specific symmetry relevant to superconductivity.

Findings

Magnon exchange induces a cos(2φ)/r^2 potential between holes.

Bound states with d-wave symmetry are formed due to this interaction.

These bound states may serve as preformed Cooper pairs in high-Tc superconductors.

Abstract

The long-range forces between holes in an antiferromagnet are due to magnon exchange. The one-magnon exchange potential between two holes is proportional to cos(2\phi)/r^2 where r is the distance vector of the holes and \phi is the angle between r and an axis of the square crystal lattice. One-magnon exchange leads to bound states of holes with antiparallel spins resembling d-wave symmetry. The role of these bound states as potential candidates for the preformed Cooper pairs of high-temperature superconductivity is discussed qualitatively.