QUANTUM QUASI-SOLITONS IN THE TWO-DIMENSIONAL FERROMAGNETIC LATTICE WITH AN EXTERNAL FIELD

2013 ◽  
Vol 27 (09) ◽  
pp. 1350058 ◽  
Author(s):  
DE-JUN LI ◽  
BING TANG ◽  
KE HU ◽  
YI TANG

Based on the quantum theory and a simplified version of the multiple-scale method, the nonlinear excitations in a two-dimensional ferromagnetic lattice with an external magnetic field are analytically investigated. The standard two-dimensional nonlinear Schrödinger equation is obtained. Results show that the quantum quasi-soliton can exist in the two-dimensional ferromagnetic lattice. In addition, when the group velocity is equal to zero, at the boundary of the Brillouin zone, the quantum quasi-soliton becomes the quantum intrinsic localized mode.

2014 ◽  
Vol 9 (3) ◽  
pp. 75-80
Author(s):  
Aleksandr Krinitsyn ◽  
Iliya Tikhomirov ◽  
Klimentiy Yugay

The Method of Monte-Carlo calculated temperature of Berezinsky – Kosterlitz – Thouless transition in twodimensional superconductor 2nd type in the presence of an external magnetic field. It is shown that near the upper critical field filling cells with a size of ξ × ξ relation, where ξ – coherence length at a given temperature, corresponds to half. It is also shown that ТBKT decreases with increasing interaction between the vortices and antivortices and increase of the external applied magnetic field


2013 ◽  
Vol 28 (16) ◽  
pp. 1350064 ◽  
Author(s):  
CATARINA BASTOS ◽  
ORFEU BERTOLAMI ◽  
NUNO COSTA DIAS ◽  
JOÃO NUNO PRATA

We consider a noncommutative description of graphene. This description consists of a Dirac equation for massless Dirac fermions plus noncommutative corrections, which are treated in the presence of an external magnetic field. We argue that, being a two-dimensional Dirac system, graphene is particularly interesting to test noncommutativity. We find that momentum noncommutativity affects the energy levels of graphene and we obtain a bound for the momentum noncommutative parameter.


2015 ◽  
Vol 15 (1) ◽  
pp. 41-48 ◽  
Author(s):  
Matthias Ratajczak ◽  
Thomas Wondrak ◽  
Klaus Timmel ◽  
Frank Stefani ◽  
Sven Eckert

AbstractIn continuous casting DC magnetic fields perpendicular to the wide faces of the mold are used to control the flow in the mold. Especially in this case, even a rough knowledge of the flow structure in the mold would be highly desirable. The contactless inductive flow tomography (CIFT) allows to reconstruct the dominating two-dimensional flow structure in a slab casting mold by applying one external magnetic field and by measuring the flow-induced magnetic fields outside the mold. For a physical model of a mold with a cross section of 140 mm×35 mm we present preliminary measurements of the flow field in the mold in the presence of a magnetic brake. In addition, we show first reconstructions of the flow field in a mold with the cross section of 400 mm×100 mm demonstrating the upward scalability of CIFT.


2012 ◽  
Vol 152 (14) ◽  
pp. 1221-1229 ◽  
Author(s):  
Hai-Feng Zhang ◽  
Shao-Bin Liu ◽  
Xiang-Kun Kong ◽  
Bo-Rui Bian ◽  
Ya-Nan Guo

2021 ◽  
pp. 2150413
Author(s):  
Hamdy I. Abdel-Gawad

The ferromagnetism induced by an external magnetic field (EMF), in (3+1) dimensions, is governed by Kraenkel–Manna–Merle system (KMMS). A (1+1) dimension model equation was derived in the literature. The magnetic moments are parallel to the magnetic field in ferromagnetism as they are aligning in the same direction of the external field. Here, it is shown that the KMMS supports the presence of internal magnetic field. This may be argued to medium characteristics. The objective of this work is to mind multiple soliton solutions, which are obtained via the generalized together with extended unified methods. Graphical representation of the results are carried. They describe infinite soliton shapes, which arise from the multiple variation of the arbitrary functions in the solutions. It is, also, shown that internal magnetic field decays, asymptotically, to zero with time.


2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Mahla Mirzaee-Kakhki ◽  
Adrian Ernst ◽  
Daniel de las Heras ◽  
Maciej Urbaniak ◽  
Feliks Stobiecki ◽  
...  

Abstract Detailed control over the motion of colloidal particles is relevant in many applications in colloidal science such as lab-on-a-chip devices. Here, we use an external magnetic field to assemble paramagnetic colloidal spheres into colloidal rods of several lengths. The rods reside above a square magnetic pattern and are transported via modulation of the direction of the external magnetic field. The rods behave like bipeds walking above the pattern. Depending on their length, the bipeds perform topologically distinct classes of protected walks. We design parallel polydirectional modulation loops of the external field that command up to six classes of bipeds to walk on distinct predesigned paths. Using such loops, we induce the collision of reactant bipeds, their polymerization addition reaction to larger bipeds, the separation of product bipeds from the educts, the sorting of different product bipeds, and also the parallel writing of a word consisting of several letters. Our ideas and methodology might be transferred to other systems for which topological protection is at work.


Sign in / Sign up

Export Citation Format

Share Document