We use the integrated polarized radio emission at 1.4 GHz ($Pi_{rm 1.4,GHz}$) from a large sample of AGN (796 sources at redshifts $z<0.7$) to study the large-scale magnetic field properties of radio galaxies in relation to the host galaxy accretion
state. We find a fundamental difference in $Pi_{rm 1.4,GHz}$ between radiative-mode AGN (i.e. high-excitation radio galaxies, HERGs, and radio-loud QSOs) and jet-mode AGN (i.e. low-excitation radio galaxies, LERGs). While LERGs can achieve a wide range of $Pi_{rm 1.4,GHz}$ (up to $sim$$30%$), the HERGs and radio-loud QSOs are limited to $Pi_{rm 1.4,GHz} lesssim 15%$. A difference in $Pi_{rm 1.4,GHz}$ is also seen when the sample is divided at 0.5% of the total Eddington-scaled accretion rate, where the weakly accreting sources can attain higher values of $Pi_{rm 1.4,GHz}$. We do not find any clear evidence that this is driven by intrinsic magnetic field differences of the different radio morphological classes. Instead, we attribute the differences in $Pi_{rm 1.4,GHz}$ to the local environments of the radio sources, in terms of both the ambient gas density and the magnetoionic properties of this gas. Thus, not only are different large-scale gaseous environments potentially responsible for the different accretion states of HERGs and LERGs, we argue that the large-scale magnetised environments may also be important for the formation of powerful AGN jets. Upcoming high angular resolution and broadband radio polarization surveys will provide the high precision Faraday rotation measure and depolarization data required to robustly test this claim.
Spin waves have been studied experimentally and by simulations in 1000 nm side equilateral triangular Permalloy dots in the Buckle state (B, with in-plane field along the triangle base) and the Y state (Y, with in-plane field perpendicular to the bas
e). The excess of exchange energy at the triangles edges creates channels that allow effective spin wave propagation along the edges inthe B state. These quasi one-dimensional spin waves emitted by the vertex magnetic charges gradually transform from propagating to standing due to interference and(as pointed out by simulations) areweakly affected by smallvariations of the aspect ratio(from equilateral to isosceles dots) or by interdot dipolar interaction present in our dot arrays. Spin waves excited in the Y state have mainly a two-dimensional character.Propagation of the spin waves along the edge states in triangular dots opens possibilities for creation of new and versatile spintronic devices.
Broadband magnetization response of equilateral triangular 1000 nm Permalloy dots has been studied under an in-plane magnetic field, applied parallel (buckle state) and perpendicular (Y state) to the triangles base. Micromagnetic simulations identify
edge spin waves (E-SWs) in the buckle state as SWs propagating along the two adjacent edges. These quasi one-dimensional spin waves emitted by the vertex magnetic charges gradually transform from propagating to standing due to interference and are weakly affected by dipolar interdot interaction and variation of the aspect ratio. Spin waves in the Y state have a two dimensional character. These findings open perspectives for implementation of the E-SWs in magnonic crystals and thin films.
We study a hundred of galaxies from the spectroscopic Sloan Digital Sky Survey with individual detections in the Far-Infrared Herschel PACS bands (100 or 160 $mu$m) and in the GALEX Far-UltraViolet band up to z$sim$0.4 in the COSMOS and Lockman Hole
fields. The galaxies are divided into 4 spectral and 4 morphological types. For the star forming and unclassifiable galaxies we calculate dust extinctions from the UV slope, the H$alpha$/H$beta$ ratio and the $L_{rm IR}/L_{rm UV}$ ratio. There is a tight correlation between the dust extinction and both $L_{rm IR}$ and metallicity. We calculate SFR$_{total}$ and compare it with other SFR estimates (H$alpha$, UV, SDSS) finding a very good agreement between them with smaller dispersions than typical SFR uncertainties. We study the effect of mass and metallicity, finding that it is only significant at high masses for SFR$_{Halpha}$. For the AGN and composite galaxies we find a tight correlation between SFR and L$_{IR}$ ($sigmasim$0.29), while the dispersion in the SFR - L$_{UV}$ relation is larger ($sigmasim$0.57). The galaxies follow the prescriptions of the Fundamental Plane in the M-Z-SFR space.
We study the interplay between gas phase metallicity (Z), specific star formation rate (SSFR) and neutral hydrogen gas (HI) for galaxies of different stellar masses. Our study uses spectroscopic data from GAMA and SDSS star forming galaxies, as well
as HI-detection from the ALFALFA and GASS public catalogues. We present a model based on the Z-SSFR relation that shows that at a given stellar mass, depending on the amount of gas, galaxies will follow opposite behaviours. Low-mass galaxies with a large amount of gas will show high SSFR and low metallicities, while low-mass galaxies with small amounts of gas will show lower SSFR and high metallicities. In contrast, massive galaxies with a large amount of gas will show moderate SSFR and high metallicities, while massive galaxies with small amounts of gas will show low SSFR and low metallicities. Using ALFALFA and GASS counterparts, we find that the amount of gas is related to those drastic differences in Z and SSFR for galaxies of a similar stellar mass.
We study transport of non-interacting electrons through two quantum dot molecules embedded in an Aharonov-Bohm interferometer. The system in equilibrium exhibits bound states in the continuum (BIC) and total suppression of transmission. It also shows
a magnetic flux-dependent effective level attraction and lines of perfect transmission when the intramolecular coupling is weak. Out of equilibrium, the current displays two kind of negative differential conductance (NDC) regions, which have different origins. One is generated by the usual mechanism of the NDC arising in a double quantum dot system. The other is induced by the magnetic flux, and it occurs at small voltages and for a well definite range of the intramolecular couplings. We explain this effect in terms of the level attraction displayed by the system.
Electron tunneling through a two stage Kondo system constituted by a double quantum-dot molecule side coupled to a quantum wire, under the effect of a finite external potential is studied. We found that $I$-$V$ characteristic shows a negative differe
ntial conductance region induced by the electronic correlation. This phenomenon is a consequence of the properties of the two stage Kondo regime under the effect of an external applied potential that takes the system out of equilibrium. The problem is solved using the mean-field finite-$U$ slave-boson formalism.
