Competition between the Spin and Pseudospin Subsystems in a Model Cuprate

• Published in: Physics of the solid state Vol. 61; no. 5; pp. 707 - 713
• Main Authors: Panov, Yu. D., Ulitko, V. A., Budrin, K. S., Yasinskaya, D. N., Chikov, A. A.
• Format: Journal Article
• Language: English
• Published: Moscow Pleiades Publishing 01.05.2019; Springer; Springer Nature B.V
• Subjects: ANTIFERROMAGNETISM; CHARGE EXCHANGE; Comparative analysis; Competition; Computer simulation; COMPUTERIZED SIMULATION; CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; CUPRATES; Exchanging; IMPURITIES; ISING MODEL; LIQUIDS; Magnetism; MAGNETIZATION; Mathematical models; MEAN-FIELD THEORY; MONTE CARLO METHOD; Numerical analysis; Phase separation; Physics; Physics and Astronomy; Solid State Physics; SPIN; Subsystems; Two dimensional models
• ISSN: 1063-7834; 1090-6460
• DOI: 10.1134/S106378341905024X

The competition between the magnetic and charge orderings in a model cuprate is considered in terms of a simplified static 2D spin–pseudospin model. This model is equivalent to the 2D dilute antiferromagnetic (AFM) Ising model with charged impurities. The mean-field approximation results are presented for the system under study and briefly compared to the classical Monte Carlo (MC) calculations. The numerical simulation shows that the cases of the strong exchange and the strong charge correlation differ qualitatively. In the case of a strong exchange, the AMF phase is instable with respect to the phase separation (PS) into the pseudospin (charge) and magnetic (spin) subsystems that behave as immiscible quantum liquids. The analytical expression has been obtained for the PS temperature.