Quantum Skyrmions and the Destruction of Antiferromagnetic Order in High-Temperature Superconductors

TL;DR

This paper presents a field theory model showing how doping in high-temperature superconductors creates skyrmion excitations that lead to the destruction of antiferromagnetic order at a critical doping level, matching experimental data.

Contribution

It introduces a continuous field theory linking doping to skyrmion creation and predicts the critical doping level for antiferromagnetic order destruction, aligning with experiments.

Findings

Critical doping level $oxed{oxed{ ext{0.39} ext{ to } ext{0.42}}}$ matches experimental $oxed{ ext{0.41} ext{ to } ext{0.43}}$.

Skyrmion energy vanishes at the critical doping, indicating magnetic order breakdown.

Doping induces topological excitations responsible for phase transition.

Abstract

A continuous field theory which describes the process of doping in high-T$_c$ superconductors of the YBCO-type is presented. It is shown that the introduction of dopants produces the creation of skyrmion topological excitations on the antiferromagnetic background. The energy of these excitations is evaluated. Destruction of the N\'eel ground state occurs for a critical value $\delta_C$ of the doping parameter for which the skyrmion energy vanishes. We evaluate this at zero temperature, obtaining $\delta_C = 0.39 \pm 0.03$ which agrees with the experimental value $\delta_C^{exp} = 0.41 \pm 0.02$.