Search results for "ROOM-TEMPERATURE"
showing 10 items of 18 documents
Chlorophyll fluorescence emission spectrum inside a leaf
2008
International audience; Chlorophyll a fluorescence can be used as an early stress indicator. Fluorescence is also connected to photosynthesis so it can be proposed for global monitoring of vegetation status from a satellite platform. Nevertheless, the correct interpretation of fluorescence requires accurate physical models. The spectral shape of the leaf fluorescence free of any re-absorption effect plays a key role in the models and is difficult to measure. We present a vegetation fluorescence emission spectrum free of re-absorption based on a combination of measurements and modelling. The suggested spectrum takes into account the photosystem I and II spectra and their relative contributio…
From magnetic to nonlinear optical switches in spin-crossover complexes
2013
ISI Document Delivery No.: 109TF Times Cited: 0 Cited Reference Count: 173 Lacroix, Pascal G. Malfant, Isabelle Real, Jose-Antonio Rodriguez, Vincent Wiley-v c h verlag gmbh Weinheim Si; Various attempts to combine magnetic and nonlinear optical (NLO) properties in a molecule are reviewed, with a special focus on the possibility of interplay between the magnetic component and the quadratic (proportional to E-2) NLO response. This multidisciplinary research leads to the idea of spin-crossover-induced (SCO-induced) NLO switching and is evaluated at the synthetic level, with insights provided by computational chemistry. The need for nontraditional experimental setups to record NLO properties i…
Skyrmion pinning energetics in thin film systems
2022
AbstractA key issue for skyrmion dynamics and devices are pinning effects present in real systems. While posing a challenge for the realization of conventional skyrmionics devices, exploiting pinning effects can enable non-conventional computing approaches if the details of the pinning in real samples are quantified and understood. We demonstrate that using thermal skyrmion dynamics, we can characterize the pinning of a sample and we ascertain the spatially resolved energy landscape. To understand the mechanism of the pinning, we probe the strong skyrmion size and shape dependence of the pinning. Magnetic microscopy imaging demonstrates that in contrast to findings in previous investigation…
The 2020 skyrmionics roadmap
2020
The notion of non-trivial topological winding in condensed matter systems represents a major area of present-day theoretical and experimental research. Magnetic materials offer a versatile platform that is particularly amenable for the exploration of topological spin solitons in real space such as skyrmions. First identified in non-centrosymmetric bulk materials, the rapidly growing zoology of materials systems hosting skyrmions and related topological spin solitons includes bulk compounds, surfaces, thin films, heterostructures, nano-wires and nano-dots. This underscores an exceptional potential for major breakthroughs ranging from fundamental questions to applications as driven by an inte…
A weakly-interacting many-body system of Rydberg polaritons based on electromagnetically induced transparency
2020
We proposed utilizing a medium with a high optical depth (OD) and a Rydberg state of low principal quantum number, $n$, to create a weakly-interacting many-body system of Rydberg polaritons, based on the effect of electromagnetically induced transparency (EIT). We experimentally verified the mean field approach to weakly-interacting Rydberg polaritons, and observed the phase shift and attenuation induced by the dipole-dipole interaction (DDI). The DDI-induced phase shift or attenuation can be viewed as a consequence of the elastic or inelastic collisions among the Rydberg polaritons. Using a weakly-interacting system, we further observed that a larger DDI strength caused a width of the mome…
Two-Step Solution-Processed Two-Component Bilayer Phthalocyaninato Copper-Based Heterojunctions with Interesting Ambipolar Organic Transiting and Eth…
2016
International audience; The two-component phthalocyaninato copper-based heterojunctions fabricated from n-type CuPc(COOC8H17)(8) and p-type CuPc(OC8H17)(8) by a facile two-step solution-processing quasi-Langmuir-Shafer method with both n/p- and p/n-bilayer structures are revealed to exhibit typical ambipolar air-stable organic thin-film transistor (OTFT) performance. The p/n-bilayer devices constructed by depositing CuPc(COOC8H17)(8) film on CuPc(OC8H17)(8) sub-layer show superior OTFT performance with hole and electron mobility of 0.11 and 0.02 cm(2) V-1 s(-1), respectively, over the ones with n/p-bilayer heterojunction structure with the hole and electron mobility of 0.03 and 0.016 cm(2) …
Independent Geometrical Control of Spin and Charge Resistances in Curved Spintronics
2019
Spintronic devices operating with pure spin currents represent a new paradigm in nanoelectronics, with higher energy efficiency and lower dissipation as compared to charge currents. This technology, however, will be viable only if the amount of spin current diffusing in a nanochannel can be tuned on demand while guaranteeing electrical compatibility with other device elements, to which it should be integrated in high-density three-dimensional architectures. Here, we address these two crucial milestones and demonstrate that pure spin currents can effectively propagate in metallic nanochannels with a three-dimensional curved geometry. Remarkably, the geometric design of the nanochannels can b…
The three-dimensional structure of Drosophila melanogaster (6–4) photolyase at room temperature
2021
A crystal structure of a photolyase at room temperature confirms the structural information obtained from cryogenic crystallography and paves the way for time-resolved studies of the photolyase at an X-ray free-electron laser.
Magnetoelectric coupling driven by inverse magnetostriction in multiferroic BiMn3Mn4O12
2013
By means of neutron powder diffraction, we investigated the effect of the polar Bi$^{3+}$ ion on the magnetic ordering of the Mn$^{3+}$ ions in BiMn$_3$Mn$_4$O$_{12}$, the counterpart with \textit{quadruple} perovskite structure of the \textit{simple} perovskite BiMnO$_3$. The data are consistent with a \textit{noncentrosymmetric} spacegroup $Im$ which contrasts the \textit{centrosymmetric} one $I2/m$ previously reported for the isovalent and isomorphic compound LaMn$_3$Mn$_4$O$_{12}$, which gives evidence of a Bi$^{3+}$-induced polarization of the lattice. At low temperature, the two Mn$^{3+}$ sublattices of the $A'$ and $B$ sites order antiferromagnetically (AFM) in an independent manner …
Spin crossover star-shaped metallomesogens of iron(II).
2014
Three new types of spin crossover (SCO) metallomesogens of Fe-II based on symmetric tripod ligands and their magnetic and structural properties are reported here. These were obtained by condensation of tris(2-aminoethyl)-amin (tren) with the aldehyde derived from 3-alkoxy-6-methylpyridine (mpyN, N (number of carbon atoms in n-alkyl chains) = 8, 18), 1-alkyl-1H-imidazole (imN, N = 4, 16, 18, 20, 22), or 1-alkyl-1H-benzimidazole (bimN, N = 6, 14, 16, 18, 20). A complex derived from 1-octadecyl-1H-naphtho[2,3-d]imidazole (nim18) retains the high spin state at any temperature. Single crystals of the short-chain complexes were investigated by a combination of X-ray crystallography, magnetic meas…