Article
Crystallography
Ka-Ming Tam, Hanna Terletska, Tom Berlijn, Liviu Chioncel, Juana Moreno
Summary: A real space cluster extension method was developed to study Anderson localization, successfully capturing the phenomena in all disorder regimes. The approach accurately obtained the critical disorder strength for 3D Anderson localization and systematically recovered the re-entrance behavior of the mobility edge. This methodology offers potential to study Anderson localization at surfaces within quantum embedding theory, allowing for the exploration of the interplay between topology and Anderson localization from first principles.
Article
Materials Science, Multidisciplinary
Qi Wei, Jianxiong Zhai, Zhijun Ning, Youqi Ke
Summary: We present a generalized auxiliary coherent medium theory to address the long-standing challenge of simulating Anderson-type off-diagonal disorder (AODD) in disordered alloys. By transforming AODD into a diagonal-like disorder with a weighted discrete distribution in an auxiliary medium, we show that our approach substantially improves the accuracy of simulating the phonon linewidth in NiFe and NiPt alloys, compared to results obtained with averaged-value off-diagonal disorder (ODD). This paper provides an effective approach for dealing with large fluctuations in ODD in disordered materials, representing an important progress for mean-field simulations in the embedding framework.
Article
Physics, Multidisciplinary
H. Terletska, A. Moilanen, K-M Tam, Y. Zhang, Y. Wang, M. Eisenbach, N. S. Vidhyadhiraja, L. Chioncel, J. Moreno
Summary: The study utilizes a finite cluster typical medium approach to investigate the Anderson localization transition in three dimensions, demonstrating fast convergence and the importance of typical medium environment and non-local spatial correlations. The method can recover the correct critical disorder strength as the cluster size increases, highlighting the significance of non-local cluster corrections for capturing mobility edge trajectories of the localization behavior. The findings suggest that the typical medium cluster approach developed provides a consistent and systematic description of the Anderson localization transition within the framework of effective medium embedding schemes.
Article
Materials Science, Multidisciplinary
Philip M. Dee, Steven Johnston, Thomas A. Maier
Summary: This study investigates the effect of coupling a metal on the superconducting transition temperature of an unconventional superconductor. The results show a nonmonotonic dependence of the transition temperature on the strength of hybridization and interlayer hopping.
Article
Physics, Multidisciplinary
Gianluca D'Addese, Laura Sani, Luca La Rocca, Roberto Serra, Marco Villani
Summary: The study proposes a methodology for identifying emergent structures in complex systems by modeling the system state as a set of random variables. A sieving algorithm is used to compare subsets of variables based on an information-theoretic measure of coordination, allowing for fair comparisons of subsets with different cardinalities. Increasing the number of observations enables the identification of larger subsets in the system.
Article
Energy & Fuels
Haoran Song, Baiquan Lin, Zheng Zhong, Ting Liu
Summary: This study tested the pore structure of typical coals with different metamorphic degrees and investigated the factors affecting the diffusion property of methane. The results show that the pore structure affects the diffusion resistance and initial diffusion rate of methane. The metamorphic degree and size of the coal samples also have a significant impact on the diffusion behavior of methane.
Article
Automation & Control Systems
Marianne Souaiby, Aneel Tanwani, Didier Henrion
Summary: In this study, we investigate the time evolution of a probability measure for a class of state-constrained dynamical systems described by evolution variational inequalities. Unlike smooth ordinary differential equations, the evolution of this probability measure is not necessarily invertible due to the nonsmooth nature of the differential inclusion. Instead, we approximate the original nonsmooth system using Lipschitz approximation and construct a sequence of measures obtained from Liouville equations. This sequence converges to the measure describing the evolution of the distribution of states for the original nonsmooth system, allowing us to numerically approximate the evolution of moments.
Article
Ergonomics
Di Pan, Yong Han, Qianqian Jin, He Wu, Hongwu Huang
Summary: The study developed a set of typical AEB test scenarios for ETWs using accident data with video information, aiming to enhance collision safety.
ACCIDENT ANALYSIS AND PREVENTION
(2021)
Article
Engineering, Civil
Li Fu, Qiangsheng Yin, Hikaru Nakamura, Yoshihito Yamamoto, Taito Miura
Summary: This study investigated the deterioration mechanism of shear performance caused by rebar cut-off setting for RC beams and the reinforcing mechanism of stirrups against rebar cut-off setting. The results showed that the application of stirrups can suppress the adverse effects of cut-off setting and improve the ductile performance of beam specimens.
Article
Chemistry, Physical
Tobias Schafer, Florian Libisch, Georg Kresse, Andreas Gruneis
Summary: An embedding approach is presented to efficiently handle local electron correlation effects in periodic environments by integrating high-level correlation calculations into low-level ones. The method demonstrates accelerated convergence with respect to the local fragment size and has shown capabilities in accurately calculating adsorption energies of molecules and lattice impurities in solids.
JOURNAL OF CHEMICAL PHYSICS
(2021)
Article
Physics, Fluids & Plasmas
Qian Wang, Francisco Perez-Bernal
Summary: Using diagonal entropy, efficient indicators of the presence of ESQPT in the Lipkin-Meshkov-Glick model were identified through time evolution analysis. The probability distribution of diagonal entropy values over a certain time interval distinguished clearly between different phases of ESQPT, with a universal form observed at the critical point, described by a beta distribution. Reliable detection of ESQPT was found to be obtainable from central moments of the diagonal entropy.
Article
Chemistry, Physical
Scott Habershon
Summary: The study demonstrates that a program synthesis approach based on a linear code representation can be used to generate algorithms that approximate the ground-state solutions of one-dimensional time-independent Schrodinger equations. Discrete optimization with simulated annealing is used to identify code sequences that can reproduce the expected ground-state wavefunctions for target PESs. This alternative method shows promise for developing novel algorithms for quantum chemistry applications.
JOURNAL OF CHEMICAL PHYSICS
(2021)
Article
Physics, Nuclear
Sahila Chopra, Manoj K. Sharma, Peter Oto Hess, Jasleen Bedi
Summary: According to different theoretical studies, the next magicity for the proton number should occur at Z = 114, 120, or 126 and for the neutron number N = 184. This work investigates the synthesis of superheavy element 120 via the Ni-64 + U-238 reaction, focusing on the fission and quasifission cross sections. The results show that the formation possibility of compound nucleus Z = 120 from the Ni-induced reaction is very low.
Article
Chemistry, Multidisciplinary
Donat J. Adams, Sergey V. Churakov
Summary: Perovskites ABX(3) with delocalized positions of the X atoms represent a distinct class of dynamically distorted structures with peculiar structural relations and physical properties. The delocalization originates from atoms crossing shallow barriers of the potential energy surface. Many of these perovskite structures are widely used functional materials thanks to their particular physical properties, such as superconductivity, ferroelectricity and photoactivity. Yet, a full understanding of the relationships between perovskite crystal structure, chemical bonding and physical properties is currently missing.
Article
Meteorology & Atmospheric Sciences
Michael A. Barnes, Kate Turner, Thando Ndarana, Willem A. Landman
Summary: The study analyzed the impact of an intense surface low pressure system and cut-off low that affected the south-western Cape of South Africa in June 2017. The Cape Storm resulted in heavy rains, strong winds, wildfires, storm surge, and large waves, causing loss of life and damage to infrastructure. Analysis from a potential vorticity perspective showed that Rossby wave breaking and high-potential vorticity from the stratosphere influenced the development of the storm.
ATMOSPHERIC RESEARCH
(2021)
Article
Physics, Multidisciplinary
H. Terletska, A. Moilanen, K-M Tam, Y. Zhang, Y. Wang, M. Eisenbach, N. S. Vidhyadhiraja, L. Chioncel, J. Moreno
Summary: The study utilizes a finite cluster typical medium approach to investigate the Anderson localization transition in three dimensions, demonstrating fast convergence and the importance of typical medium environment and non-local spatial correlations. The method can recover the correct critical disorder strength as the cluster size increases, highlighting the significance of non-local cluster corrections for capturing mobility edge trajectories of the localization behavior. The findings suggest that the typical medium cluster approach developed provides a consistent and systematic description of the Anderson localization transition within the framework of effective medium embedding schemes.
Article
Multidisciplinary Sciences
Ka-Ming Tam, Nicholas Walker, Juana Moreno
Summary: In the US, different states have adopted different policies and timing for easing COVID-19 mitigation measures, resulting in significant differences between actual death counts and projected figures. The study finds that mandating face masks shows the strongest correlation with the number of deaths.
SCIENTIFIC REPORTS
(2022)
Article
Materials Science, Multidisciplinary
Mariia Karabin, Wasim Raja Mondal, Andreas Oestlin, Wai-Ga D. Ho, Vladimir Dobrosavljevic, Ka-Ming Tam, Hanna Terletska, Liviu Chioncel, Yang Wang, Markus Eisenbach
Summary: We compared different modeling approaches to study the electronic properties of the Hf0.05Nb0.05Ta0.8Ti0.05Zr0.05 high-entropy alloy. The special quasi-random structures modeling and the supercell method provided similar results for the ground state properties, and we found possible superconductivity in the alloy.
JOURNAL OF MATERIALS SCIENCE
(2022)
Review
Quantum Science & Technology
Herbert F. Fotso, Ka-Ming Tam, Juana Moreno
Summary: This article discusses the challenges of strongly correlated systems, the importance of computational methods in addressing these challenges, and the development and application of multiscale many-body methods.
QUANTUM SCIENCE AND TECHNOLOGY
(2022)
Article
Crystallography
Nicholas Walker, Samuel Kellar, Yi Zhang, Ka-Ming Tam, Juana Moreno
Summary: This paper presents a neural network solver for the single impurity Anderson model, demonstrating its accurate results in calculating the spectral function. This opens the possibility of utilizing the neural network approach for other many-body numerical methods.
Article
Crystallography
Samuel Kellar, Ka-Ming Tam, Juana Moreno
Summary: We numerically study a three-dimensional strongly correlated system and find evidence of a separatrix between Fermi liquid and non-Fermi liquid regions by fitting the quasi-particle weight to the marginal Fermi liquid form at finite doping near the putative quantum critical point. Our results suggest the existence of a marginal Fermi liquid and possibly a quantum critical point in the non-symmetry broken solution of the three-dimensional interacting electron systems.
Article
Physics, Fluids & Plasmas
Anshumitra Baul, Nicholas Walker, Juana Moreno, Ka-Ming Tam
Summary: We generalize the application of variational autoencoders to the anisotropic two-dimensional Ising model and provide numerical evidence that a variational autoencoder can be applied to analyze quantum systems. We reproduce the phase diagram without the explicit construction of an order parameter and demonstrate the validity of using a variational autoencoder to characterize anisotropic classical and quantum models.
Article
Materials Science, Multidisciplinary
Sergei Iskakov, Hanna Terletska, Emanuel Gull
Summary: This study compares twist-averaging and the dynamical cluster approximation variant of the dynamical mean field theory, and compares them to the standard periodic boundary technique. It is found that while all methods converge to the same limit, the convergence speed differs in practice. Embedding theories are shown to be effective in managing finite size effects.
Article
Materials Science, Multidisciplinary
Eric Dohner, Hanna Terletska, Ka-Ming Tam, Juana Moreno, Herbert F. Fotso
Summary: We present a solution for the nonequilibrium dynamics of an interacting disordered system by adapting the equilibrium dynamical mean-field theory and the equilibrium coherent potential approximation methods. Our approach uses the Kadanoff-Baym-Keldysh complex time contour to study the dynamics of interacting disordered systems away from equilibrium. We obtain the equilibrium density of states of the disordered interacting system and observe the effect of disorder on the relaxation of the system.
Proceedings Paper
Computer Science, Software Engineering
Sirazum Munira Tisha, Rufino A. Oregon, Gerald Baumgartner, Fernando Alegre, Juana Moreno
Summary: Automatic grading systems help reduce the burden of manual grading, but existing systems have limited scope in judging code quality. This study proposes an autograder that can effectively evaluate the code quality of visual outputs created by high school students in a computational thinking course, and experimental results demonstrate its effectiveness.
2022 IEEE/ACM 4TH INTERNATIONAL WORKSHOP ON SOFTWARE ENGINEERING EDUCATION FOR THE NEXT GENERATION (SEENG 2022)
(2022)
Article
Materials Science, Multidisciplinary
B. D. E. McNiven, Hanna Terletska, G. T. Andrews, J. P. F. LeBlanc
Summary: In this study, we investigate the properties of the t-t'-U Hubbard model on a two-dimensional square lattice in the weak-coupling limit using a direct perturbative approach. We find that for nonzero t', the resonance excitations exhibit different behaviors at different densities, which are related to the van Hove singularity of the noninteracting dispersion. We also observe a significant reduction in compressibility and a behavioral change in double occupancy near the van Hove singularity.
Proceedings Paper
Computer Science, Interdisciplinary Applications
Yu Chen, Lori Martin, John Underwood, Fernando Alegre, Alicia Whidden, Mahannah El-Farrah, Juana Moreno
Summary: This study focused on teachers' experiences in implementing culturally relevant pedagogy (CRP) in grade 6-12 computing classrooms. Some teachers tended to understand cultural differences from a color-blind perspective, and due to limited resources, teachers often found it difficult to enrich students' learning experiences by adding individualized culturally relevant components.
IEEE STCBP RESPECT CONFERENCE: 2021 RESEARCH ON EQUITY AND SUSTAINED PARTICIPATION IN ENGINEERING, COMPUTING, AND TECHNOLOGY (RESPECT)
(2021)
Article
Materials Science, Multidisciplinary
Hanna Terletska, Sergei Iskakov, Thomas Maier, Emanuel Gull
Summary: In this study, the phase transitions and mechanisms of electron localization in the extended Hubbard model were examined using the dynamical cluster approximation on a 2 x 2 cluster. The interplay of charge order and Mott physics was explored, with findings showing the effects of nearest-neighbor Coulomb interaction V on correlations in metallic and insulating regimes, as well as the different correlation aspects of charge order and Mott states.
