Effect of the Canting of Local Anisotropy Axes on Ground-State Properties of a Ferrimagnetic Chain with Regularly Alternating Ising and Heisenberg Spins

The effect of the canting of local anisotropy axes on the ground-state phase diagram and magnetization of a ferrimagnetic chain with regularly alternating Ising and Heisenberg spins is exactly examined in an arbitrarily oriented magnetic field. It is shown that individual contributions of Ising and Heisenberg spins to the total magnetization basically depend on the spatial orientation of the magnetic field and the canting angle between two different local anisotropy axes of the Ising spins.Comment: 3 pages, 3 figure

Pairwise thermal entanglement in Ising-XYZ diamond chain structure in an external magnetic field

Quantum entanglement is one of the most fascinating types of correlation that can be shared only among quantum systems. The Heisenberg chain is one of the simplest quantum chains which exhibits a reach entanglement feature, due to the Heisenberg interaction is quantum coupling in the spin system. The two particles were coupled trough XYZ coupling or simply called as two-qubit XYZ spin, which are the responsible for the emergence of thermal entanglement. These two-qubit operators are bonded to two nodal Ising spins, and this process is repeated infinitely resulting in a diamond chain structure. We will discuss two-qubit thermal entanglement effect on Ising-XYZ diamond chain structure. The concurrence could be obtained straightforwardly in terms of two-qubit density operator elements, using this result, we study the thermal entanglement, as well as the threshold temperature where entangled state vanishes. The present model displays a quite unusual concurrence behavior, such as, the boundary of two entangled regions becomes a disentangled region, this is intrinsically related to the XY-anisotropy in the Heisenberg coupling. Despite a similar property had been found for only two-qubit, here we show in the case of a diamond chain structure, which reasonably represents real materials.Comment: 6 pages, 7 figure

Urban Policies and Health In Developing Countries: The Case of Maputo (Mozambique) and Cochabamba (Bolivia)

Urban planning and related policies can contribute to improvement in health. Recent epidemiological and quantitative Health Impact Assessment (HIA) studies in Europe and North America suggest that a change from passive (car) to active transportation (cycling, walking) and public transport in daily life could improve health. HIA studies are still largely lacking in low and middle-income countries. We conducted a scoping study to evaluate the availability of data to conduct quantitative HIA in two cities from two low-income countries. We collected information through interviews with different local agents, from the National Institute of Statistics and by conducting field work to identify the built environment and mobility characteristics in the respective cities. Conducting a quantitative HIA in Maputo (Mozambique) is currently not possible, mainly because there is no appropriate data on mortality, road traffic accidents and physical activity of the general population. However, in Cochabamba (Bolivia) it might be possible when the mobility plan will be available (currently under development), in which data on traffic flows, mobility surveys and transport modal shares will become available. The current paper describes two examples of the opportunities and difficulties to conduct quantitative HIA in low- and middle-income countries, highlighting the limited availability of data (quantitatively and qualitatively) on transport and urban planning and health outcomes