scholarly journals Ground-state properties of the one-dimensional transverse Ising model in a longitudinal magnetic field

2019 ◽  
Vol 99 (1) ◽  
Author(s):  
O. F. de Alcantara Bonfim ◽  
B. Boechat ◽  
J. Florencio
Keyword(s):  
Magnetic Field ◽  
Ising Model ◽  
Ground State ◽  
Longitudinal Magnetic Field ◽  
One Dimensional ◽  
Transverse Ising Model ◽  
Ground State Properties ◽  
The One

scholarly journals Exact Ground-State Properties and Phase Transitions within One-dimensional Hubbard Model in Magnetic Field

2000 ◽  
Vol 14 (29n31) ◽  
pp. 3771-3776
Author(s):  
C. Yang ◽  
A. N. Kocharian ◽  
Y. L. Chiang
Keyword(s):  
Magnetic Field ◽  
Hubbard Model ◽  
Ground State ◽  
Chemical Potential ◽  
Interaction Strength ◽  
Upper And Lower Bounds ◽  
One Dimensional ◽  
Ground State Properties ◽  
Half Filling ◽  
The One

The phase diagram, the Bethe-ansatz ground-state properties, including the chemical potential μ, the spin (magnetic) and charge susceptibilities, are calculated within the one-dimensional Hubbard model in entire range of interaction strength (-∞< U/t<+∞), magnetic field (h≥ 0) and all electron concentrations (0≤n≤1). The continuous and smooth variation of μ with n and h in the vicinity of n=1 points on the gapless character of charge excitations at U<0 and provides rigorous upper and lower bounds for μ. The spin (magnetic) susceptability χ at half-filling changes discontinuously as U→0 and is strongly enhanced by electron repulsion, comparing with that of the non-interactig case. The compressibility κ ch increases with n at U<0 and shows non-monotonous behavior with a dramatic increase at U>0. Variations of κ ch -1 in both repulsive and attractive cases qualitatively well reproduces corresponding behavior of charge stiffness.

EXACT GROUND-STATE PROPERTIES OF ONE-DIMENSIONAL HUBBARD MODEL IN THE PRESENCE OF MAGNETIC FIELD

1999 ◽  
Vol 13 (29n31) ◽  
pp. 3573-3578
Author(s):  
C. Yang ◽  
A. N. Kocharian ◽  
Y. L. Chiang
Keyword(s):  
Magnetic Field ◽  
Hubbard Model ◽  
Ground State ◽  
Interaction Strength ◽  
Magnetic Saturation ◽  
One Dimensional ◽  
Ground State Properties ◽  
Wide Range ◽  
Average Spin ◽  
The One

The exact phase diagram and the ground-state properties of the one-dimensional Hubbard model with arbitrary on-site interaction of electrons are calculated over a wide range of magnetic field and electron concentrations by means of the Bethe-ansatz formalism. The ground-state properties, including the total energy, the average spin (magnetization) and spin (magnetic) susceptibility are investigated for both signs of the interaction strength U/t. The critical behavior near the onset of magnetization and magnetic saturation are also analyzed. At the onset of magnetization and near the magnetic saturation the spin susceptibility χ diverges at all U/t for half-filling case n=1, whereas for n≠1 it is always finite. The reverse susceptibility χ-1(U) exhibits anomalous hump, which increases with h or n, and shows discontinuity as U/t→±0 at infinitesimal h→0. The analytical results for the ground-state properties in strong and weak interaction limits are in full agreement with our numerical calculations.

Investigation of the Finite Size Properties of the Ising Model Under Various Boundary Conditions

2020 ◽  
Vol 75 (2) ◽  
pp. 175-182
Author(s):  
Magdy E. Amin ◽  
Mohamed Moubark ◽  
Yasmin Amin
Keyword(s):  
Magnetic Field ◽  
Ising Model ◽  
Boundary Conditions ◽  
Finite Size ◽  
Scaling Functions ◽  
Finite Size Scaling ◽  
One Dimensional ◽  
Various Boundary Conditions ◽  
The One ◽  
Bulk Case

AbstractThe one-dimensional Ising model with various boundary conditions is considered. Exact expressions for the thermodynamic and magnetic properties of the model using different kinds of boundary conditions [Dirichlet (D), Neumann (N), and a combination of Neumann–Dirichlet (ND)] are presented in the absence (presence) of a magnetic field. The finite-size scaling functions for internal energy, heat capacity, entropy, magnetisation, and magnetic susceptibility are derived and analysed as function of the temperature and the field. We show that the properties of the one-dimensional Ising model is affected by the finite size of the system and the imposed boundary conditions. The thermodynamic limit in which the finite-size functions approach the bulk case is also discussed.

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