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
Materials Science, Multidisciplinary
Pietro F. Fontana, Ask H. Larsen, Thomas Olsen, Kristian S. Thygesen
Summary: A type of Wannier functions obtained by minimizing the conventional spread function with a penalty term proportional to the spread distribution's variance is introduced, along with an automatic protocol for selecting initial guesses and determining the optimal number of bands. The improved performance and robustness of the approach is demonstrated in various test systems.
Article
Physics, Multidisciplinary
Pratik Sathe, Fenner Harper, Rahul Roy
Summary: Wannier functions play a crucial role in understanding properties of crystalline materials, with the ability to be exponentially localized and even more compactly supported in certain cases. This paper addresses the general conditions for constructing compactly supported Wannier functions, particularly in 1D non-interacting tight-binding models. It shows that the strict locality of the projection operator is necessary and sufficient for a subspace to be spanned by a compactly supported orthogonal basis.
JOURNAL OF PHYSICS A-MATHEMATICAL AND THEORETICAL
(2021)
Article
Computer Science, Interdisciplinary Applications
Guo-Xiang Zhi, Chenchao Xu, Si-Qi Wu, Fanlong Ning, Chao Cao
Summary: The explicit expressions of symmetry operators on Wannier basis are derived and implemented in the WannSymm software, allowing for symmetrization of real-space Hamiltonian, generation of symmetry operators of little group at specific k-point, and symmetry analysis for Wannier band structure. Symmetrized Hamiltonians yield improved results when employed for nodal structure searching, surface Green's function calculations, and other model calculations.
COMPUTER PHYSICS COMMUNICATIONS
(2022)
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
Multidisciplinary Sciences
Chenwei Lv, Ren Zhang, Zhengzheng Zhai, Qi Zhou
Summary: The authors establish a duality between non-Hermiticity and curved spaces, revealing a geometric root of non-Hermitian phenomena and providing a method to study and tailor non-Hermiticity using curved spaces.
NATURE COMMUNICATIONS
(2022)
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
Stefano Longhi
Summary: The energy bands of non-Hermitian systems have nontrivial topological features that result from the complex nature of the energy spectrum, characterized by integer nonzero winding numbers. The nontrivial winding provides the topological signature of the non-Hermitian skin effect (NHSE) at lattice edges under open boundary conditions. While most current results rely on tight-binding models of non-Hermitian systems, exact Bloch wave function analysis of the NHSE and related topological band theory is still lacking.
Article
Physics, Multidisciplinary
Pavel A. Nosov, Ivan M. Khaymovich, Andrey Kudlis, Vladimir E. Kravtsov
Summary: The accuracy of the forward scattering approximation for two-point Green's functions of the Anderson localization model on the Cayley tree is analyzed. The relationship between the moments of the Green's function and the largest eigenvalue of the linearized transfer-matrix equation is proved, and a new approximation for this eigenvalue is derived. It is shown that the FSA overestimates the probability of the Green's function being significantly larger than its typical value.
Article
Materials Science, Multidisciplinary
Way Wang, Zhongshui Ma
Summary: This article discusses two core concepts in low-dimensional condensed matter physics: localization phenomena and quantum phase transition. Taking vortex line pinning in superconductors as an example, the article studies the relationship between localization transition problem and quantum phase transition by mapping it to a non-Hermitian problem. It explores the phase transitions induced by interactions and shows the existence of classical and quantum regimes in the phase diagram, with the quantum regime exhibiting a nonchaotic first-order phase transition.
Article
Mathematics, Applied
Paul Hagelstein, Giorgi Oniani
Summary: Besicovitch proved that if f is an integrable function on R2 with finite strong maximal function MSf a.e., then the integral off is strongly differentiable. On the other hand, Papoulis proved the existence of an integrable function on R2 whose integral is strongly differentiable but with infinite associated strong maximal function on a set of positive measure. In this paper, we prove that if n >= 2 and if f is a measurable nonnegative function on Rn with strongly differentiable integral and f(1 + log+ f)n-2 integrable, then MSf is finite a.e. We also show that this result is sharp by constructing a function f satisfying certain conditions.
JOURNAL OF MATHEMATICAL ANALYSIS AND APPLICATIONS
(2023)
Article
Chemistry, Physical
Emil Vinas Bostroem, Adithya Sriram, Martin Claassen, Angel Rubio
Summary: Harnessing light-matter coupling and quantum vacuum fluctuations in optical cavities can control the magnetic state and stabilize specific magnetic phases in correlated magnetic systems, enabling functionalization of quantum materials and the realization of exotic states of matter.
NPJ COMPUTATIONAL MATERIALS
(2023)
Article
Materials Science, Multidisciplinary
Edinardo I. B. Rodrigues, Mauro M. Doria
Summary: This paper reports an infinite number of orthonormal eigenfunction bases suitable for describing doubly periodic electronic densities in a quantum system of a free electron in the presence of an external magnetic field. The completeness of these bases is demonstrated, with a single basis expanding any function in the unit cell based on the number of magnetic fluxons trapped in the unit cell. The framework reveals an egg-box pattern for the electronic density displaying fractional charge and magnetic flux, and for electrons confined to the lowest Landau level, an analytic expression for the local magnetic field created by their own motion is obtained, showing an attractive magnetic interaction. The well-known de Haas-van Alphen oscillations are also retrieved, confirming the correctness of the theoretical framework presented.
Article
Materials Science, Multidisciplinary
G. Bouzerar
Summary: This study reveals that in flat-band systems, randomly distributed vacancies can boost the conductivity, especially at low density. This phenomenon challenges our understanding of physical phenomena, and the singular behavior of the quantum metric is found to be crucial.
Article
Multidisciplinary Sciences
Darshana Wickramaratne, I. I. Mazin
Summary: In this study, the authors provide an alternative explanation for the non-monotonic behavior of the superconducting transition temperature in NbSe2-xSx monolayer alloys based on the effects of alloying and defects on the electronic structure and magnetism.
NATURE COMMUNICATIONS
(2022)
