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Particle-Hole Asymmetric Ferromagnetism and Spin Textures in the Triangular Hubbard-Hofstadter Model
In a lattice model subject to a perpendicular magnetic field, when the lattice constant is comparable to the magnetic length, one enters the “Hofstadter regime,” where continuum Landau levels become fractal magnetic Bloch bands. Strong mixing between bands alters the nature of the resulting quantum phases compared to the continuum limit; lattice potential, magnetic field, and Coulomb interaction must be treated on equal footing. Using determinant quantum Monte Carlo and density matrix renormalization group techniques, we study this regime numerically in the context of the Hubbard-Hofstadter model on a triangular lattice. In the field-filling phase diagram, we find a broad wedge-shaped region of ferromagnetic ground states for filling factor ν ≤ 1 , bounded below by filling factor ν = 1 and bounded above by half filling the lowest Hofstadter subband. We observe signatures of SU(2) quantum Hall ferromagnetism at filling factors ν = 1 and ν = 3 . The phases near ν = 1 are particle-hole asymmetric, and we observe a rapid decrease in ground-state spin polarization consistent with the formation of skyrmions only on the electron doped side. At large fields, above the ferromagnetic wedge, we observe a low-spin metallic region with spin correlations peaked at small momenta. We argue that the phenomenology of this region likely results from exchange interaction mixing fractal Hofstadter subbands. The phase diagram derived beyond the continuum limit points to a rich landscape to explore interaction effects in magnetic Bloch bands. Published by the American Physical Society 2024
Ferroelectric C-Axis Textured Aluminum Scandium Nitride Thin Films of 100 nm Thickness
We report on the properties of Aluminum Scandium Nitride (AlScN) thin films deposited by pulsed-DC co-sputtering. We present the impact of the nitrogen-to-argon gas ratio on the crystal growth orientation, film stress, surface roughness, scandium concentration, and deposition rate of 760-860 nm thick AlScN thin films on Ti/Pt (111). We utilize the optimized process conditions from this study to deposit thin layers of AlScN and to explore the nucleation and orientation of thin AlScN layers on Ti/Pt (111). We report on the ferroelectric properties of 100 nm thick AlScN materials.
Light Trapping Textures Designed by Electromagnetic Optimization for Subwavelength Thick Solar Cells
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Highly Textured IrMn 3 (111) Thin Films Grown by Magnetron Sputtering
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Remote Sensing Image Segmentation by Combining Spectral and Texture Features
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Environmental insights from high-resolution (SIMS) sulfur isotope analyses of sulfides in Proterozoic microbialites with diverse mat textures
Not provided.
Piezoelectric K[subscript 0.5]Na[subscript 0.5]NbO[subscript 3] Ceramics Textured Using Needlelike K[subscript 0.5]Na[subscript 0.5]NbO[subscript 3] Templates
Abstract not provided
Effect of Mechanical Constraint on Domain Reorientation in Predominantly {111}-Textured Lead Zirconate Titanate Films
Abstract not provided
Using a mixture of hydrocolloids to mimic texture and rheological properties of a massive consumption food product
Not Available
Assessment of Photovoltaic Surface Texturing on Transmittance Effects and Glint/Glare Impacts.
Abstract not provided.
Epitaxial to axiotaxial texture evolution in endotaxial MnP films grown on GaP (100)
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SU-F-R-08: Can Normalization of Brain MRI Texture Features Reduce Scanner-Dependent Effects in Unsupervised Machine Learning?
Purpose: To reduce differences in features calculated from MRI brain scans acquired at different field strengths with or without Gadolinium contrast. Methods: Brain scans were processed for 111 epilepsy patients to extract hippocampus and thalamus features. Scans were acquired on 1.5 T scanners with Gadolinium contrast (group A), 1.5T scanners without Gd (group B), and 3.0 T scanners without Gd (group C). A total of 72 features were extracted. Features were extracted from original scans and from scans where the image pixel values were rescaled to the mean of the hippocampi and thalami values. For each data set, cluster analysis was performed on the raw feature set and for feature sets with normalization (conversion to Z scores). Two methods of normalization were used: The first was over all values of a given feature, and the second by normalizing within the patient group membership. The clustering software was configured to produce 3 clusters. Group fractions in each cluster were calculated. Results: For features calculated from both the non-rescaled and rescaled data, cluster membership was identical for both the non-normalized and normalized data sets. Cluster 1 was comprised entirely of Group A data, Cluster 2 contained data from all three groups, and Cluster 3 contained data from only groups 1 and 2. For the categorically normalized data sets there was a more uniform distribution of group data in the three Clusters. A less pronounced effect was seen in the rescaled image data features. Conclusion: Image Rescaling and feature renormalization can have a significant effect on the results of clustering analysis. These effects are also likely to influence the results of supervised machine learning algorithms. It may be possible to partly remove the influence of scanner field strength and the presence of Gadolinium based contrast in feature extraction for radiomics applications.
Observation of mirror-odd and mirror-even spin texture in ultrathin epitaxially strained RuO2 films
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Quantitative 3D petrography using X-ray tomography 4: Assessing glass inclusion textures with propagation phase-contrast tomography
Abstract not provided
Modification of the structural, textural, and mechanical properties of an Al{sub 2}O{sub 3}/Al composite on the addition of an Al-SBA-15-type mesoporous phase
The formation of the pore structure of metal–ceramic materials based on Al{sub 2}O{sub 3}/Al composites has been studied in detail by modifying them via the incorporation of SBA-15-type mesoporous materials. The composition, pore structure, pore size, and morphology of the composite particles have been studied using nitrogen adsorption/desorption isotherms, scanning electron microscopy, and X-ray diffraction. We have produced Al-SBA-15/Al{sub 2}O{sub 3}/Al monoliths that combine properties of both adsorbents and permeable materials, but the incorporation of Al-SBA-15 into an Al{sub 2}O{sub 3}/Al matrix reduces the permeability and mechanical strength of the composites.
The Effect of Base Thickness on Photoconversion Efficiency in Textured Silicon-Based Solar Cells
A theory is developed, which describes the experimental external quantum efficiency, EQE(λ) as a function of photon wavelength for structured Si-based solar cells. Short-circuit current density as a function of base thickness, d, is calculated for the high-efficiency solar cells with the photoconversion efficiency η ≥ 25% The procedure allows one to carry out a complete optimization of such solar cells, in particular, to find the optimal base thickness, d{sub opt}.