Short-range spin- and pair-correlations: a variational wave-function

TL;DR

The paper introduces a versatile variational wave-function capable of describing both superconducting and spin correlations, capturing key features of high-Tc cuprates' phase diagram, including the interplay of superconductivity and antiferromagnetism.

Contribution

It proposes a new general wave-function that models complex correlations in high-Tc cuprates, unifying superconducting and magnetic states within a single framework.

Findings

Superposition of spin states S=0 and S=1 in Cooper pairs.

Continuous super-symmetric rotation linking s-wave superconductivity and antiferromagnetism.

Wave-function captures essential aspects of the high-Tc cuprates' phase diagram.

Abstract

A many-body wavefuction is postulated, which is sufficiently general to describe superconducting pair-correlations, and/or spin-correlations, which can occur either as long-range order or as finite-range correlations. The proposed wave-function appears to summarize some of the more relevant aspects of the rich phase-diagram of the high-Tc cuprates. Some of the states represented by this wavefunction are reviewed: For superconductivity in the background of robust anti-ferromagnetism, the Cooper-pairs are shown to be a superposition of spinquantum numbers S=0 and S=1. If the anti-ferromagnetism is weak, a continuous super-symmetric rotation is identified connecting s-wave superconductivity to anti-ferromagnetism.