Thermodynamic properties of Heisenberg magnetic systems

Abstract

In this paper, we present a comprehensive investigation of the effects of the transverse correlation function (TCF) on the thermodynamic properties of Heisenberg antiferromagnetic (AFM) and ferromagnetic (FM) systems with cubic lattices. The TCF of an FM system is positive and increases with temperature, while that of an AFM system is negative and decreases with temperature. The TCF lowers internal energy, entropy and specific heat. It always raises the free energy of an FM system but raises that of an AFM system only above a specific temperature when the spin quantum number is S ≥ 1. Comparisons between the effects of the TCFs on the FM and AFM systems are made where possible.

The thermodynamic properties of a spin-1/2 Heisenberg ferromagnetic system using Oguchi's method

“…The thermodynamic properties of the magnetic system have been studied by many authors both experimentally [1][2][3][4] and theoretically [5][6][7][8][9][10][11]. Effective field theories generally used to describe these thermodynamic properties.…”

Antiferromagnetic Dispersion Relations and Nature of Magnon Pressure

“…The impact of external magnetic fields on antiferromagnetic systems -both in two and three spatial dimensions -has been studied by various authors employing different techniques: (modified) spin-wave theory [1][2][3][4][5][6][7][8][9][10][11], Green's functions [12][13][14][15][16], series expansions [17][18][19][20], Monte Carlo simulations [21][22][23], exact diagonalization [24,25], and yet other methods [26][27][28][29][30][31][32][33][34][35][36][37].…”

Population dynamics of excited atoms in non-Markovian environments at zero and finite temperature

“…[21] However, the atomic spontaneous emission and the environment-induced dissipation inevitably lead to decoherence and noise in the quantum system and thus are undesirable in the above quantum physics researches. Recently, non-Markovianities of open quantum systems have been extensively studied [22][23][24][25][26][27] and a theoretical approach for treating quantum transport was given in Ref. [28].…”