Article
Computer Science, Interdisciplinary Applications
Takashi Koretsune
Summary: In this study, two methods for constructing Maximally localized Wannier functions (MLWFs) using crystal symmetry are presented. The first method calculates input matrices for generating MLWFs based on wavefunctions in the irreducible Brillouin zone (IBZ), resulting in reduced computational costs and file sizes. The second method involves calculating symmetry-adapted Wannier functions compatible with the frozen window technique. Examples of Fe, Co3Sn2S2, Cu, and Nb are demonstrated. These methods are implemented in the PW2WANNIER90 code, which interfaces QUANTUM-ESPRESSO with WANNIER90, and the open-source python library, SYMWANNIER.
COMPUTER PHYSICS COMMUNICATIONS
(2023)
Article
Chemistry, Physical
Junfeng Qiao, Giovanni Pizzi, Nicola Marzari
Summary: Researchers have developed an automated method to generate maximally localized Wannier functions that accurately describe both occupied and unoccupied states. They have also proposed an algorithm to construct manifold-remixed functions by mixing these Wannier functions, aiming to describe specific target groups of bands.
NPJ COMPUTATIONAL MATERIALS
(2023)
Article
Materials Science, Multidisciplinary
J. D. Fuhr, P. Roura-Bas, A. A. Aligia
Summary: First-principles calculations were used to analyze the behavior of stanene in different phases as it undergoes a topological phase transition under the influence of an external electric field. It was found that the system is in a topological phase when the critical field is approximately 0.69 eV/angstrom for the more realistic MLWF, suggesting greater stability on inert substrates compared to a multiorbital tight-binding model.
Article
Materials Science, Multidisciplinary
Hang Liu, Gurjyot Sethi, Sheng Meng, Feng Liu
Summary: This article introduces a generic atomic/molecular orbital design principle for flat bands (FBs) in non-LG lattices, demonstrating the transformation of wave-function symmetry of FBs in a LG lattice into atomic/molecular orbital symmetry in a non-LG lattice. The designed orbitals faithfully reproduce the corresponding lattice symmetries in three different 2D non-LG lattices, and systematic design of FBs with a high Chern number is also achieved based on the same principle.
Article
Materials Science, Multidisciplinary
Kevin D. Stubbs, Alexander B. Watson, Jianfeng Lu
Summary: In this study, the problem of calculating exponentially localized generalized Wannier functions in various systems is addressed and the Iterated Projected Position (IPP) algorithm is introduced as a solution. Numerical experiments demonstrate the efficacy of the IPP algorithm in computing exponentially localized bases for different models.
Article
Computer Science, Theory & Methods
Andrea Mesiarova-Zemankova
Summary: This paper discusses the monotonicity of functions defined on the unit interval constructed via the (z)-ordinal sum. In Part I, all non-decreasing functions constructed by a non-trivial ordinal sum of semigroups on the unit interval are characterized, and necessary and sufficient conditions for a function constructed via ordinal sum to be monotone are given. In Part II, the structure of a monotone function constructed via the z-ordinal sum with respect to a finite branching set is described, and necessary and sufficient conditions for a function constructed via z-ordinal sum to be monotone when the intermediate condition is fulfilled are provided. The case when the intermediate condition is not fulfilled is also discussed.
FUZZY SETS AND SYSTEMS
(2023)
Article
Computer Science, Theory & Methods
Andrea Mesiarova-Zemankova
Summary: This paper is the second part of a two-part series, focusing on the monotonicity of functions defined on the unit interval using (z)-ordinal construction. In Part I, we characterized all non-decreasing functions constructed by a non-trivial ordinal sum of semigroups and provided necessary and sufficient conditions for a function constructed via ordinal sum to be monotone. In Part II, we explore the structure of monotone functions constructed via z-ordinal sum with respect to a finite branching set, and we present necessary and sufficient conditions for monotonicity when the intermediate condition is fulfilled. We also discuss the case when the intermediate condition is not fulfilled.
FUZZY SETS AND SYSTEMS
(2023)
Article
Computer Science, Artificial Intelligence
Andrea Mesiarova-Zemankova
Summary: The n-uninorms with continuous underlying t-norms and t-conorms are characterized using the z-ordinal sum construction. It is shown that each of these uninorms can be expressed as a z-ordinal sum of a countable number of Archimedean and idempotent semigroups with respect to a branching set A, similar to {z(1), ..., z(n-1)}, where the corresponding partial order has a tree structure.
INTERNATIONAL JOURNAL OF APPROXIMATE REASONING
(2021)
Article
Physics, Mathematical
I. Marquette, C. Quesne
Summary: This paper re-examines a shape invariant nonseparable and nondiagonalizable two-dimensional model with anharmonic complex interaction and provides an algebraic construction of the associated functions to the excited-state wavefunctions. The introduction of a novel pair of operators complements the existing raising and lowering operators, making the construction of associated functions more efficient. The results obtained extend the previous findings for the quartic anharmonic oscillator by considering additional excited states or adding higher order terms to the Hamiltonian.
REPORTS ON MATHEMATICAL PHYSICS
(2022)
Article
Computer Science, Artificial Intelligence
Francesco Conti, Patrizio Frosini, Nicola Quercioli
Summary: This paper introduces a new method for constructing non-linear GEOs and non-linear GENEOs based on symmetric functions and permutants. The technique is proven to be applicable to any symmetric function, and the obtained GENEOs may have potential applications in Topological Data Analysis.
FRONTIERS IN ARTIFICIAL INTELLIGENCE
(2022)
Article
Computer Science, Hardware & Architecture
Hui Ge, Zepeng Zhuo, Xiaoni Du
Summary: This paper presents a general construction method to obtain odd-variable SAO resilient Boolean functions using the modified High-Meets-Low technique, without directly using PW functions or KY functions. It is shown that the new class of functions has higher resiliency order and higher SAO nonlinearity than the known functions, with the resiliency order increasing rapidly with the variable number n.
IEICE TRANSACTIONS ON FUNDAMENTALS OF ELECTRONICS COMMUNICATIONS AND COMPUTER SCIENCES
(2023)
Article
Plant Sciences
Min Li, Si-qi Shen, Yi-bin Xing, Wan-wan Jiao, Yong-rui Zhan, Ya-dan Sun, Da-long Guo, Yi-He Yu
Summary: The study revealed that the VvPUB17 gene enhances grapevine resistance to powdery mildew through the SA signal pathway. Transgenic plants with elevated levels of key genes related to the SA defense pathway and high concentrations of salicylic acid exhibited increased resistance to powdery mildew.
JOURNAL OF BERRY RESEARCH
(2021)
Article
Physics, Multidisciplinary
Alexander Edstrom, Claude Ederer
PHYSICAL REVIEW LETTERS
(2020)
Article
Materials Science, Multidisciplinary
Ankit Izardar, Claude Ederer
PHYSICAL REVIEW MATERIALS
(2020)
Article
Materials Science, Multidisciplinary
Sophie Beck, Claude Ederer
PHYSICAL REVIEW MATERIALS
(2020)
Article
Physics, Condensed Matter
Sophie Beck, Alexander Hampel, Olivier Parcollet, Claude Ederer, Antoine Georges
Summary: We present a fully self-consistent implementation of dynamical mean field theory combined with density functional theory for electronic structure calculations of materials with strong electronic correlations. The implementation is integrated into open source software packages, uses hdf5 archive interface to eliminate file parsing, and shows good consistency in benchmark tests.
JOURNAL OF PHYSICS-CONDENSED MATTER
(2022)
Article
Materials Science, Multidisciplinary
Alberto Carta, Claude Ederer
Summary: Using density-functional theory(DFT) and its extension to DFT + U, a possible scenario for a strain-induced metal-insulator transition in SrCrO3 thin films is proposed. The emergence of a Jahn-Teller(JT) distortion is disfavored due to the energetic overlap of the d(xz)/d(yz) band with the lower-lying d(xy) band. Tensile epitaxial strain lowers the energy of the d(xy) band, which allows the material to open up a gap in the electronic band structure.
PHYSICAL REVIEW MATERIALS
(2022)
Article
Physics, Nuclear
Marcus Scheck, Robert Chapman, Jacek Dobaczewski, Claude Ederer, Peter Ivanov, Guiseppe Lorusso, David O'Donnell, Christian Schroder
Summary: This work proposes a new approach to search for CP-violating odd-electric and even-magnetic nuclear moments. The quadrupole-deformed and octupole-correlated nucleus 227-actinium is a potential candidate to find such moments. By analyzing the recoil-free self-absorption technique, specifically Mossbauer spectroscopy, on the 27.4keV E1 transition between the 3/2(+) parity-doublet partner and the 3/2(-) ground state, the lower limit of triangle E = 2 center dot gamma is estimated to be 23.7(1) x10(-9) eV for the achievable energy resolution. This work presents the first ideas on the patterns caused by CP-violating moments on the quadrupole splitting and nuclear Zeeman effect.
EUROPEAN PHYSICAL JOURNAL A
(2023)
Article
Physics, Multidisciplinary
Peter Mlkvik, Claude Ederer, Nicola A. Spaldin
Summary: We conducted a density-functional theory study on the structural, electronic, and chemical bonding behavior of Ge-doped VO2. The results show that the doping of Ge disrupts the rutile phase and induces structural distortions resembling the insulating structure observed in experiments. These findings may explain the observed increase in transition temperature under Ge doping.
PHYSICAL REVIEW RESEARCH
(2022)
Article
Physics, Multidisciplinary
Rong Zhang, Maximilian E. Merkel, Sophie Beck, Claude Ederer
Summary: In this study, we address the problem of analytic continuation of imaginary-frequency Green's functions in many-body physics. We use a machine learning approach based on a multilevel residual neural network and consider potential biases introduced by training the network on artificially created spectral functions. We also implement an uncertainty estimation of the predicted spectral function and study the effect of noise during training. Our analysis shows that this method can achieve high-quality predictions comparable to or better than the widely used maximum entropy method, but further improvement is limited by the lack of true training data.
PHYSICAL REVIEW RESEARCH
(2022)
Article
Physics, Multidisciplinary
Mayan Si, Ankit Izardar, Claude Ederer
Summary: This study investigates how deviations from perfect chemical order affect the magnetocrystalline anisotropy energy (MAE) in L1(0) FeNi using first-principles calculations. The authors analyze the local chemical environment of Fe atoms and find a specific nearest neighbor configuration that leads to higher MAE than the perfectly ordered system. However, a systematic analysis indicates only a partial correlation between local environment and MAE. The authors also find that increasing the Fe content can increase the MAE in the system.
PHYSICAL REVIEW RESEARCH
(2022)
Article
Materials Science, Multidisciplinary
Ankit Izardar, Claude Ederer
Summary: This study investigates the effect of chemical disorder on the magnetic exchange couplings and the Curie temperature (Tc) in L1(0)-ordered FeNi using first-principles-based calculations. The results show a strong variation in the dominant first-nearest neighbor Fe-Fe interaction for different inequivalent Fe-Fe pairs. Monte Carlo simulations indicate that such strong variations in exchange couplings can lead to a 10% reduction in Tc relative to the average coupling.
Article
Materials Science, Multidisciplinary
Maximilian E. Merkel, Claude Ederer
Summary: This study explores the transition to a charge-disproportionated insulating phase in transition-metal perovskites with d4 occupation using dynamical mean-field theory to obtain the phase diagram based on the average local Coulomb repulsion U and the Hund's coupling J. The phase diagram shows the competition between different spin states and the presence of two distinct insulating phases: the standard homogeneous Mott insulator and the inhomogeneous charge-disproportionated insulator, also known as Hund's insulator. The results are consistent with previous studies and show the unconventional nature of the Hund's insulating state.
Article
Physics, Multidisciplinary
Jaime Souto-Casares, Nicola A. Spaldin, Claude Ederer
Summary: Using a combination of DFT and DMFT, the study investigates the effect of oxygen vacancies on the electronic properties of strontium titanate. It is found that the excess charge introduced by oxygen vacancies can lead to either a state with double occupation of the localized defect state or a state with a singly occupied vacancy and one electron transferred to the conduction band. The balance between these two states depends on the strength of interaction on the vacancy and Ti sites, as well as the Ti-Ti distance across the vacancy.
PHYSICAL REVIEW RESEARCH
(2021)
Article
Physics, Multidisciplinary
Alexander Edstroem, Claude Ederer
PHYSICAL REVIEW RESEARCH
(2020)
Article
Physics, Multidisciplinary
Alexander Hampel, Sophie Beck, Claude Ederer
PHYSICAL REVIEW RESEARCH
(2020)
Article
Materials Science, Multidisciplinary
Xiangzhou Zhu, Alexander Edstrom, Claude Ederer