Compositional uniformity, domain patterning and the mechanism underlying nano-chessboard arrays

We propose that systems exhibiting compositional patterning at the nanoscale, so far assumed to be due to some kind of ordered phase segregation, can be understood instead in terms of coherent, single phase ordering of minority motifs, caused by some constrained drive for uniformity. The essential features of this type of arrangements can be reproduced using a superspace construction typical of uniformity-driven orderings, which only requires the knowledge of the modulation vectors observed in the diffraction patterns. The idea is discussed in terms of a simple two dimensional lattice-gas model that simulates a binary system in which the dilution of the minority component is favored. This simple model already exhibits a hierarchy of arrangements similar to the experimentally observed nano-chessboard and nano-diamond patterns, which are described as occupational modulated structures with two independent modulation wave vectors and simple step-like occupation modulation functions.Comment: Preprint. 11 pages, 11 figure

Quantum tunneling of the interfaces between normal-metal and superconducting regions of a type-I Pb superconductor

Evidence of a non-thermal magnetic relaxation in the intermediate state of a type-I superconducor is presented. It is attributed to quantum tunneling of interfaces separating normal and superconducting regions. Tunneling barriers are estimated and temperature of the crossover from thermal to quantum regime is obtained from Caldeira-Leggett theory. Comparison between theory and experiment points to tunneling of interface segments of size comparable to the coherence length, by steps of order one nanometer

Temporal Interpolation of Dynamic Digital Humans using Convolutional Neural Networks

In recent years, there has been an increased interest in point cloud representation for visualizing digital humans in cross reality. However, due to their voluminous size, point clouds require high bandwidth to be transmitted. In this paper, we propose a temporal interpolation architecture capable of increasing the temporal resolution of dynamic digital humans, represented using point clouds. With this technique, bandwidth savings can be achieved by transmitting dynamic point clouds in a lower temporal resolution, and recreating a higher temporal resolution on the receiving side. Our interpolation architecture works by first downsampling the point clouds to a lower spatial resolution, then estimating scene flow using a newly designed neural network architecture, and finally upsampling the result back to the original spatial resolution. To improve the smoothness of the results, we additionally apply a novel technique called neighbour snapping. To be able to train and test our newly designed network, we created a synthetic point cloud data set of animated human bodies. Results from the evaluation of our architecture through a small-scale user study show the benefits of our method with respect to the state of the art in scene flow estimation for point clouds. Moreover, correlation between our user study and existing objective quality metrics confirm the need for new metrics to accurately predict the visual quality of point cloud contents

Field induced magnetic transition and metastability in Co substituted Mn2SbMn_{2}Sb

A detailed investigation of first order ferrimagnetic (FRI) to antiferromagnetic (AFM) transition in Co (15%) doped $Mn_2Sb$ is carried out. These measurements demonstrate anomalous thermomagnetic irreversibility and glass-like frozen FRI phase at low temperatures. The irreversibility arising between the supercooling and superheating spinodals is distinguised in an ingenious way from the irreversibility arising due to kinetic arrest. Field annealing measurements shows reentrant FRI-AFM-FRI transition with increasing temperature. These measurements also show that kinetic arrest band and supercooling band are anitcorrelated i.e regions which are kinetically arrested at higher temperature have lower supercooling temperature and vice versa.Comment: 10 pages, 8 figure