Electronic states around a vortex core in high-Tc superconductors based on the t-J model

TL;DR

This study uses the two-dimensional t-J model to analyze electronic states around vortex cores in high-Tc superconductors, explaining the suppression of zero-energy peaks and the role of antiferromagnetic correlations.

Contribution

It demonstrates that the reduction of zero-energy peaks is mainly due to small core size, not AF correlations, within a unified t-J model framework.

Findings

AF correlations develop inside vortex cores near optimal doping

Reduction of zero-energy peak is linked to small core size

Spatial dependence of core states correlates with core radius

Abstract

Electronic states around vortex cores in high-Tc superconductors are studied using the two-dimensional t-J model in order to treat the d-wave superconductivity with short coherence length and the antiferromagnetic (AF) instability within the same framework. We focus on the disappearance of the large zero-energy peak in the local density of states observed in high-Tc superconductors. When the system is near the optimum doping, we find that the local AF correlation develops inside the vortex cores. However, the detailed doping dependence calculations confirm that the experimentally observed reduction of the zero-energy peak is more reasonably attributed to the smallness of the core size rather than to the AF correlation developed inside the core. The correlation between the spatial dependence of the core states and the core radius is discussed.