Electronic structure and Magnetism in BaMn2_2As2_2 and BaMn2_2Sb2_2

We study the properties of ThCr$_2$Si$_2$ structure BaMn$_2$As$_2$ and BaMn$_2$Sb$_2$ using density functional calculations of the electronic and magnetic as well experimental measurements on single crystal samples of BaMn$_2$As$_2$. These materials are local moment magnets with moderate band gap antiferromagnetic semiconducting ground states. The electronic structures show substantial Mn - pnictogen hybridization, which stabilizes an intermediate spin configuration for the nominally $d^5$ Mn. The results are discussed in the context of possible thermoelectric applications and the relationship with the corresponding iron / cobalt / nickel compounds Ba(Fe,Co,Ni)$_2$As$_2$

Phytoextraction of phosphorus for ecological restoration: application of soil additives

The European Habitats Directive urges the European member states to take measures for maintaining and restoring natural habitats. In Flanders (Belgium) and the Netherlands, the surface area of nature reserves is intended to be enlarged with 38 000 ha and 150 000 ha, respectively, what is mainly to be realised on former agricultural land. In order to restore species rich nature habitats on former agricultural land, it is crucial to decrease the availability of nutrients and a limitation for plant growth by at least one nutrient should be ensured. The former fertilization of P in the agricultural context results in an immense P pool fixated to the soil and this is one of the main problems hindering the ecological restoration. We focus on an alternative restoration method, the phytoextraction of P, also P-mining. This is the deprivation of soil P with a crop with high P-use efficiency and non-P fertilization. This method allows the gradual transition from agricultural land use towards nature management. Up until now there have only been estimations of the P-mining duration time from the initial phase of the mining-process. In order to estimate the P-extraction over time the experiments take place on a soil-P-chronosequence. A controlled pot experiment was set up with soil from three former agricultural sites with different soil-P-levels, Lolium perenne was sown and chemical and biological compounds were added to enhance the bioavailability of P for plant-uptake. The additives used were two concentrations of humic acids, phosphorus solubilising bacteria and arbuscular mycorrhizal fungi. Largest effects of the soil additions on the biomass production were measured in the lowest soil-P-level. Limitation by P in the Mid and Low P soils was very pronounced. The phytoextraction of P will slow down with soil P level decreasing in time. The effect of the soil additions is discussed

Experimental demonstration of a non-destructive controlled-NOT quantum gate for two independent photon-qubits

Universal logic gates for two quantum bits (qubits) form an essential ingredient of quantum information processing. However, the photons, one of the best candidates for qubits, suffer from the lack of strong nonlinear coupling required for quantum logic operations. Here we show how this drawback can be overcome by reporting a proof-of-principle experimental demonstration of a non-destructive controlled-NOT (CNOT) gate for two independent photons using only linear optical elements in conjunction with single-photon sources and conditional dynamics. Moreover, we have exploited the CNOT gate to discriminate all the four Bell-states in a teleportation experiment.Comment: 4 pages, 4 figures, submitte

Direct fiber vector eigenmode multiplexing transmission seeded by integrated optical vortex emitters

Spatial modes have received substantial attention over the last decades and are used in optical communication applications. In fiber-optic communications, the employed linearly polarized modes and phase vortex modes carrying orbital angular momentum can be synthesized by fiber vector eigenmodes. To improve the transmission capacity and miniaturize the communication system, straightforward fiber vector eigenmode multiplexing and generation of fiber-eigenmode-like polarization vortices (vector vortex modes) using photonic integrated devices are of substantial interest. Here, we propose and demonstrate direct fiber vector eigenmode multiplexing transmission seeded by integrated optical vortex emitters. By exploiting vector vortex modes (radially and azimuthally polarized beams) generated from silicon microring resonators etched with angular gratings, we report data-carrying fiber vector eigenmode multiplexing transmission through a 2-km large-core fiber, showing low-level mode crosstalk and favorable link performance. These demonstrations may open up added capacity scaling opportunities by directly accessing multiple vector eigenmodes in the fiber and provide compact solutions to replace bulky diffractive optical elements for generating various optical vector beams

MicroRNA and mRNA expression profiling analysis revealed the regulation of plant height in Gossypium hirsutum

Novel miRNA identified in all libraries. (XLSX 12 kb