Toward a Unified Magnetic Phase Diagram of the Cuprate Superconductors

TL;DR

This paper proposes a comprehensive magnetic phase diagram for cuprate superconductors, highlighting a broad quantum-critical region with unique spin dynamics and identifying the crossover to different regimes based on doping levels.

Contribution

It introduces a unified phase diagram with a novel intermediate quantum-critical region characterized by specific spin behavior, advancing understanding of cuprate magnetic properties.

Findings

Identification of a broad quantum-critical doping region with z=1 behavior.

Relation of the spin gap to spectral weight suppression in the quantum disordered regime.

Observation of the crossover to the z=2 regime in fully doped materials.

Abstract

We propose a unified magnetic phase diagram of cuprate superconductors. A new feature of this phase diagram is a broad intermediate doping region of quantum-critical, $z=1$, behavior, characterized by temperature independent $T_1T/T_{\rm 2G}$ and linear $T_1T$, where the spin waves are not completely absorbed by the electron-hole continuum. The spin gap in the moderately doped materials is related to the suppression of the low-energy spectral weight in the quantum disordered, $z=1$, regime. The crossover to the $z=2$ regime, where $T_1T/T_{\rm 2G}^2 \simeq \mbox{const}$, occurs only in the fully doped materials.