Entanglement distribution in a two-dimensional 5-site frustrated J1−J2 spin system

2015 ◽  
Vol 13 (06) ◽  
pp. 1550047 ◽  
Author(s):  
Mojtaba Jafarpour ◽  
Soghra Ghanavati ◽  
Davood Afshar

We have studied several ground states and their entanglement structure for a two-dimensional 5-site frustrated [Formula: see text]–[Formula: see text] system in the presence and absence of an external magnetic field. We have used concurrence as a measure of bipartite entanglement and the Meyer–Wallach measure and its generalizations as the measures of multipartite entanglement. They provide a total of eight measures which lead to 30 entanglement quantities for each possible ground state. Computing these 30 quantities for several ground states, we have provided a detailed exposition of the entanglement distribution in each state. We have also categorized them into separable states, not showing entanglement for any bipartition; globally-entangled states, showing entanglement for all the bipartitions, and the states in between. It turns out that by adjusting the external magnetic field, conditioned on the values of the interaction parameters, one may generate specific ground states belonging to a specific class, appropriate for specific tasks in quantum information theory.

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

2020 ◽  
Vol 35 (33) ◽  
pp. 2050278
Author(s):  
H. Aounallah ◽  
B. C. Lütfüoğlu ◽  
J. Kříž

Generalized uncertainty principle puts forward the existence of the shortest distances and/or maximum momentum at the Planck scale for consideration. In this article, we investigate the solutions of a two-dimensional Duffin–Kemmer–Petiau (DKP) oscillator within an external magnetic field in a minimal length (ML) scale. First, we obtain the eigensolutions in ordinary quantum mechanics. Then, we examine the DKP oscillator in the presence of an ML for the spin-zero and spin-one sectors. We determine an energy eigenvalue equation in both cases with the corresponding eigenfunctions in the non-relativistic limit. We show that in the ordinary quantum mechanic limit, where the ML correction vanishes, the energy eigenvalue equations become identical with the habitual quantum mechanical ones. Finally, we employ the Euler–Mclaurin summation formula and obtain the thermodynamic functions of the DKP oscillator in the high-temperature scale.


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