Phase Transition of the Heisenberg Antiferromagnet on the Triangular Lattice in a Magnetic Field

1985 ◽  
Vol 54 (12) ◽  
pp. 4530-4538 ◽  
Author(s):  
Hikaru Kawamura ◽  
Seiji Miyashita
Keyword(s):  
Magnetic Field ◽  
Phase Transition ◽  
Triangular Lattice ◽  
Heisenberg Antiferromagnet

scholarly journals Skyrmions and Spin Waves in Magneto–Ferroelectric Superlattices

Entropy ◽  
2020 ◽  
Vol 22 (8) ◽  
pp. 862
Author(s):  
Ildus F. Sharafullin ◽  
Hung T. Diep
Keyword(s):  
Magnetic Field ◽  
Phase Transition ◽  
Triangular Lattice ◽  
Applied Field ◽  
Zero Field ◽  
Ferroelectric Films ◽  
Dm Interaction ◽  
Cubic Lattice ◽  
Simple Cubic ◽  
Simple Cubic Lattice

We present in this paper the effects of Dzyaloshinskii–Moriya (DM) magneto–electric coupling between ferroelectric and magnetic interface atomic layers in a superlattice formed by alternate magnetic and ferroelectric films. We consider two cases: magnetic and ferroelectric films have the simple cubic lattice and the triangular lattice. In the two cases, magnetic films have Heisenberg spins interacting with each other via an exchange J and a DM interaction with the ferroelectric interface. The electrical polarizations of ±1 are assumed for the ferroelectric films. We determine the ground-state (GS) spin configuration in the magnetic film and study the phase transition in each case. In the simple cubic lattice case, in zero field, the GS is periodically non collinear (helical structure) and in an applied field H perpendicular to the layers, it shows the existence of skyrmions at the interface. Using the Green’s function method we study the spin waves (SW) excited in a monolayer and also in a bilayer sandwiched between ferroelectric films, in zero field. We show that the DM interaction strongly affects the long-wave length SW mode. We calculate also the magnetization at low temperatures. We use next Monte Carlo simulations to calculate various physical quantities at finite temperatures such as the critical temperature, the layer magnetization and the layer polarization, as functions of the magneto–electric DM coupling and the applied magnetic field. Phase transition to the disordered phase is studied. In the case of the triangular lattice, we show the formation of skyrmions even in zero field and a skyrmion crystal in an applied field when the interface coupling between the ferroelectric film and the ferromagnetic film is rather strong. The skyrmion crystal is stable in a large region of the external magnetic field. The phase transition is studied.

Phase transitions in the Heisenberg model on a layered triangular lattice in a magnetic field

2021 ◽  
pp. 1-10
Author(s):  
Akai Murtazaev ◽  
Magomedzagir Badiev ◽  
Magomedsheykh Ramazanov ◽  
Magomed Magomedov
Keyword(s):  
Magnetic Field ◽  
Phase Transitions ◽  
Triangular Lattice ◽  
Heisenberg Model

scholarly journals Magnetic-field effects on p-wave phase transition in Gauss–Bonnet gravity

2014 ◽  
Vol 29 (20) ◽  
pp. 1450094 ◽  
Author(s):  
Ya-Bo Wu ◽  
Jun-Wang Lu ◽  
Yong-Yi Jin ◽  
Jian-Bo Lu ◽  
Xue Zhang ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Phase Transition ◽  
P Wave ◽  
Vector Model ◽  
Magnetic Field Effects ◽  
Complex Vector ◽  
Bonnet Gravity ◽  
Yang Mills ◽  
Wave Phase ◽  
Lowest Landau Level

In the probe limit, we study the holographic p-wave phase transition in the Gauss–Bonnet gravity via numerical and analytical methods. Concretely, we study the influences of the external magnetic field on the Maxwell complex vector model in the five-dimensional Gauss–Bonnet–AdS black hole and soliton backgrounds, respectively. For the two backgrounds, the results show that the magnetic field enhances the superconductor phase transition in the case of the lowest Landau level, while the increasing Gauss–Bonnet parameter always hinders the vector condensate. Moreover, the Maxwell complex vector model is a generalization of the SU(2) Yang–Mills model all the time. In addition, the analytical results backup the numerical results. Furthermore, this model might provide a holographic realization for the QCD vacuum instability.

INFLUENCE OF AN EXTERNAL MAGNETIC FIELD ON THE DYNAMICS OF A NEW-PHASE NUCLEUS IN THE VICINITY OF THE FIRST-ORDER PHASE TRANSITION IN MAGNETS WITH DEFECTS PRESENT

2012 ◽  
Vol 26 (28) ◽  
pp. 1250183 ◽  
Author(s):  
VLADIMIR NAZAROV ◽  
RISHAT SHAFEEV
Keyword(s):  
Magnetic Field ◽  
Phase Transition ◽  
External Magnetic Field ◽  
Magnetic Anisotropy ◽  
Spin Reorientation ◽  
Critical Fields ◽  
First Order ◽  
Phase Nucleus ◽  
First Order Phase Transition ◽  
New Phase

Theoretically, with the aid of a soliton model, the evolution of a new-phase nucleus near the first-order spin-reorientation phase transition in magnets has been investigated in an external magnetic field. The influence of an external field and one-dimensional defects of magnetic anisotropy on the dynamics of such nucleus has been demonstrated. The conditions for the localization of the new-phase nucleus in the region of the magnetic anisotropy defect and for its escape from the defect have been determined. The values of the critical fields which bring about the sample magnetization reversal have been identified and estimated.

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