Pseudo-transition between antiferromagnetic and charge orders in a minimal spin-pseudospin model of one-dimensional cuprates

TL;DR

This paper explores a pseudo-transition in a simplified one-dimensional cuprate model, revealing unusual thermodynamic behavior that mimics phase transitions but is not truly one.

Contribution

It introduces a minimal spin-pseudospin model for cuprates and characterizes the pseudo-transition using transfer-matrix methods, highlighting its unique thermodynamic signatures.

Findings

Pseudo-transition occurs between charge-ordered and antiferromagnetic phases.

Entropy and correlations change sharply near the pseudo-transition.

Specific heat exhibits a sharp peak similar to a continuous phase transition.

Abstract

This study rigorously investigates the phenomenon of a pseudo-transition in a minimal spinpseudospin model, serving as a simplified model of one-dimensional cuprate chains [CuO]n, by making use of the transfer-matrix method. The studied spin-pseudospin model of one-dimensional cuprate chains [CuO]n reveals a peculiar pseudo-transition between a charged-ordered phase and an antiferromagnetic phase, which is accompanied with anomalous behavior of magnetic and thermodynamic quantities. While the entropy and short-range correlations undergo near the pseudo-transition steep continuous changes reminiscent of a discontinuous phase transition, the specific heat displays a sizable sharp peak akin to a continuous phase transition.