Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

physica status solidi (b)

Green function theory of a semi‐infinite ising ferromagnet in a transverse field

B. A. Shiwai, Michael G Cottam

Published Apr 1, 1986• 9 citations
Publisher

Abstract

Abstract A Green function equation‐of‐motion method is employed to calculate the dynamic properties of a semi‐infinite spin system (or pseudo‐spin system) described by the Ising model in a transverse field. The excitations of the system are shown to be the bulk and surface spin waves, and the Green functions are employed to evaluate their spectral intensities and integrated power factors at temperatures above the transition temperature Tc. Some numerical examples are also included.

DOI
10.1002/pssb.2221340218

Related papers

Dynamic behaviour of the ising model in a transverse field

Anna Kühnel, S. Wendt, Julia Mihailowa Wesselinowa

Abstract The Ising model in a transverse field is treated by means of Green function technique to calculate the dynamic structure factor above and below Tc. The soft mode is overdamped in the disordered phase and near Tc, while it is nearly undamped at low temperatures. The coupling between the transverse soft mode and the relaxing longitudinal mode produces a central mode in the dynamic structure factor. The temperature dependence of the dynamic structure factor for zero wave vector is calculated numerically.

physica status solidi (b)•Dec 1, 1977•23 citations

Phase Transition for the Semi-Infinite Ising Model with a Transverse Field

Noureddine Cherkaoui Eddeqaqi, E. Ez-Zahraouy, A. Bouzid

The effect of surface and bulk transverse fields on the phase transitions of a semi-infinite spin-1 ferromagnetic Ising model is investigated within a finite cluster approximation with an expansion technique for cluster identities of spin-1 localized spin systems. The phase diagrams are determined as a function of the ratio of bulk and surface transverse fields, the temperature and the transverse field of the surface. They show that the systems exhibit a variety of phase transitions. A dead layer is also obtained in a special region of space parameters.

physica status solidi (b)•Jun 1, 1999•0 citations

Damping of the Transverse and Longitudinal Excitations of the Ising Model in a Transverse Field

Julia Mihailowa Wesselinowa

Abstract The Ising model in a transverse field is treated by means of the Green function technique to calculate the excitation spectrum and the damping of these excitations above and below Tc. The soft mode is overdamped in the disordered phase and near Tc, while it is nearly undamped at low temperatures. The temperature dependence of the transverse and longitudinal damping for zero wave vector is calculated numerically for different values of the transverse field.

physica status solidi (b)•Jan 1, 1984•8 citations

The spin correlation functions of a semi-infinite Heisenberg ferromagnet

Michael G Cottam

Results are derived for the dynamic correlation functions between a pair of spin operators at any two sites within a semi-infinite Heisenberg ferromagnet at low temperatures, T<<Tc. The correlation functions are found to contain terms describing the effects of the bulk spin-wave modes and the surface spin-wave modes, together with appropriate weighting factors. The results are employed to evaluate the spin deviation in the ferromagnet as a function of temperature and distance from the surface.

Journal of Physics C Solid State Physics•Jun 14, 1976•41 citations

Surface Magnetic Properties of a Transverse Ising Model with a Diluted Surface

Enaldo F. Sarmento, T. Kaneyoshi

Abstract Surface magnetic properties of semi‐infinite spin‐1/2 Ising ferromagnet with a diluted surface in an applied transverse field are investigated by the use of an effective‐field theory with correlations. A number of characteristic behaviors arise in the temperature and transverse field dependences of the surface magnetization. A similarity exists between the temperature plots and the transverse field plots for the surface magnetization, which proposes that the research of surface magnetization in an applied transverse field fixing temperature at a very low one may open a new method for clarifying a variety of problems in surface magnetism experimentally.

physica status solidi (b)•Jul 1, 1990•30 citations

Surface thermodynamic properties of a semi-infinite Ising ferromagnet in the presence of a surface transverse field

Qing Jiang, Zhen‐Ya Li

By use of a combination of the two-spin cluster approximation with the discretized path-integral representation, the surface phase diagrams and surface thermodynamic quantities, such as free energy, specific heat, and susceptibility, of a semi-infinite Ising ferromagnet in the presence of a surface transverse field are investigated.

Physical review. B, Condensed matter•Mar 1, 1991•18 citations
Abstract A Green function equation‐of‐motion method is employed to calculate the dynamic properties of a semi‐infinite spin system (or pseudo‐spin system) described by the Ising model in a transverse field. The excitations of the system are shown to be the bulk and surface spin waves, and the Green functions are employed to evaluate their spectral intensities and integrated power factors at temperatures above the transition temperature Tc. Some numerical examples are also included.
Abstract The Ising model in a transverse field is treated by means of Green function technique to calculate the dynamic structure factor above and below Tc. The soft mode is overdamped in the disordered phase and near Tc, while it is nearly undamped at low temperatures. The coupling between the transverse soft mode and the relaxing longitudinal mode produces a central mode in the dynamic structure factor. The temperature dependence of the dynamic structure factor for zero wave vector is calculated numerically.
The effect of surface and bulk transverse fields on the phase transitions of a semi-infinite spin-1 ferromagnetic Ising model is investigated within a finite cluster approximation with an expansion technique for cluster identities of spin-1 localized spin systems. The phase diagrams are determined as a function of the ratio of bulk and surface transverse fields, the temperature and the transverse field of the surface. They show that the systems exhibit a variety of phase transitions. A dead layer is also obtained in a special region of space parameters.
Results are derived for the dynamic correlation functions between a pair of spin operators at any two sites within a semi-infinite Heisenberg ferromagnet at low temperatures, T<<Tc. The correlation functions are found to contain terms describing the effects of the bulk spin-wave modes and the surface spin-wave modes, together with appropriate weighting factors. The results are employed to evaluate the spin deviation in the ferromagnet as a function of temperature and distance from the surface.
Abstract Surface magnetic properties of semi‐infinite spin‐1/2 Ising ferromagnet with a diluted surface in an applied transverse field are investigated by the use of an effective‐field theory with correlations. A number of characteristic behaviors arise in the temperature and transverse field dependences of the surface magnetization. A similarity exists between the temperature plots and the transverse field plots for the surface magnetization, which proposes that the research of surface magnetization in an applied transverse field fixing temperature at a very low one may open a new method for clarifying a variety of problems in surface magnetism experimentally.