Investigation of the temperature phase diagram of the 2D semi-classical ferrimagnetic J1−J2 model

Abstract

The temperature phase diagram (T over J2) of the 2D semiclassical J1 − J2 Heisenberg model is discussed. The investigation was carried out using the self-consistent Bloch equation and a quantum statistical description of the magnetization. In addition to the three states of the zero-temperature phase diagram, the J2 − T phase diagram shows two new phases, the paramagnetic phase and the semi-paramagnetic S1-Néel state. The five occurring ground states, as well as the transitions between these states, are discussed. In particular, attention is paid to the interplay between temperature and frustration.between temperature and frustration.

Nonlocality of mixtures of the ground and first excited states within J 1 −

“…Quantum systems are inherently vulnerable to environmental influences, particularly thermal noise [30,31]. In practical scenarios, many-body systems often operate at extremely low temperatures, effectively existing in a mixed quantum state comprising their lowest energy states.…”