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

Abstract

Abstract This study rigorously investigates the phenomenon of a pseudo-transition in a minimal spin-pseudospin model, serving as a simplified model of one-dimensional cuprate chains [CuO]$$_\infty $$ ∞ , by making use of the transfer-matrix method. The studied spin-pseudospin model of one-dimensional cuprate chains [CuO]$$_\infty $$ ∞ 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. Graphic Abstract A density plot of the specific heat of one-dimensional spin-pseudospin model of cuprate chain in the inter-site interaction versus temperature plane, which serves as a pseudo-phase diagram involving charged-ordered (CO) and antiferromagnetic (AF) phases