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We introduce a novel water bath hydrogenation process designed to enhance the magnetic properties and hyperfine field of Y2Fe17. The core of this process lies in the successful preparation of a new compound Y2Fe17H3.5 by introducing hydrogen in a mild water bath environment, accomplished by a chemical reaction between calcium, Y2Fe17, and ammonium acetate solution at room temperature and pressure. After hydrogen doping, cell volume expansion increased from 778.511 to 795.383 Å3, and notably, lattice expansion is anisotropic. Furthermore, saturation magnetization is increased from 103 to 134.93 emu/g, Curie temperature is increased from 320 to 461 K, and the average hyperfine field is increased from 18 to 25 T. The improvement in magnetic properties is due to the increase in Fe–Fe distance, which according to the Bethe–Slater curve leads to stronger Fe–Fe exchange interactions and enhancing ferromagnetic interactions. This work not only proposes the novel rhombohedral Y2Fe17H3.5 with excellent magnetic properties, but also provides a new method for hydrogen doping in Y2Fe17 which lays the foundation of fundamental solid state physics for further research. [ABSTRACT FROM AUTHOR]

Metal halide perovskites have brought about a disruptive shift in the field of third-generation photovoltaics. Their potential as remarkably efficient solar cell absorbers was first demonstrated in the beginning of the 2010s. However, right from their inception, persistent challenges have impeded the smooth adoption of this technology in the industry. These challenges encompass issues such as the lack of reproducibility in fabrication, limited mid- and long-term stability, and concerns over toxicity. Despite achieving record efficiencies that have outperformed even well-established technologies, such as polycrystalline silicon, these hurdles have hindered the seamless transition of this technology into industrial applications. In this Perspective, we discuss which of these challenges are rooted in the unique dual nature of metal halide perovskites, which simultaneously function as electronic and ionic semiconductors. This duality results in the intermingling of processes occurring at vastly different timescales, still complicating both their comprehensive investigation and the development of robust and dependable devices. Our discussion here undertakes a critical analysis of the field, addressing the current status of knowledge for devices based on halide perovskites in view of electronic and ionic conduction, the underlying models, and the challenges encountered when these devices are optoelectronically characterized. We place a distinct emphasis on the positive contributions that this area of research has not only made to the advancement of photovoltaics but also to the broader progress of solid-state physics and photoelectrochemistry. [ABSTRACT FROM AUTHOR]

Pressure-induced phase transformation in iron and its alloys is a classic research topic in solid-state physics, material science, and geophysics. The crystal structure of iron undergoes a phase transformation at a hydrostatic pressure of 13 GPa, changing from a body-centered cubic system to a hexagonal close-packed system. Although extensive research has been carried out on the transformation in iron by using molecular dynamics simulations, there is very limited literature that focuses on the contribution of parent phase orientations, system size, and impurities to the phase evolution. In this work, classic molecular dynamics simulations have been employed to investigate the effects of system size, lattice orientation, and impurity concentration on the pressure-induced phase transformation of iron and iron alloys for the first time. Our results show that the lattice orientation has a strong influence on the phase transition behavior, while the influence of carbon is small. The phase transition is slightly delayed with increasing carbon content, whereas the transition pressure increases from [001] to [011] to [111] orientation. The amount of twinning and stacking faults highly depends on the orientation. It is easiest for solitary waves to travel through [111] lattice orientation. The addition of carbon has a slow-down effect on shock velocities, and this effect increases with carbon content and lattice orientation of the samples from [001] to [011] to [111]. [ABSTRACT FROM AUTHOR]

The adiabatic connection interaction strength interpolation (ISI)-like method provides a high-level expression for the correlation energy, being, in principle, exact not only in the weak-interaction limit, where it recovers the second-order Görling–Levy perturbation term, but also in the strong-interaction limit that is described by the strictly correlated electron approach. In this work, we construct a genISI functional made accurate for the uniform electron gas, a solid-state physics paradigm that is a very difficult test for ISI-like correlation functionals. We assess the genISI functional for various jellium spheres with the number of electrons Z ≤ 912 and for the non-relativistic noble atoms with Z ≤ 290. For the jellium clusters, the genISI is remarkably accurate, while for the noble atoms, it shows a good performance, similar to other ISI-like methods. Then, the genISI functional can open the path using the ISI-like method in solid-state calculations. [ABSTRACT FROM AUTHOR]

The interplay of topology, magnetism, and correlations gives rise to intriguing phases of matter. In this study, through state-of-the-art angle-resolved photoemission spectroscopy, density functional theory, and dynamical mean-field theory calculations, we visualize a fourfold degenerate Dirac nodal line at the boundary of the bulk Brillouin zone in the antiferromagnet YMn2Ge2. We further demonstrate that this gapless, antiferromagnetic Dirac nodal line is enforced by the combination of magnetism, space-time inversion symmetry, and nonsymmorphic lattice symmetry. The corresponding drumhead surface states traverse the whole surface Brillouin zone. YMn2Ge2 thus serves as a platform to exhibit the interplay of multiple degenerate nodal physics and antiferromagnetism. Interestingly, the magnetic nodal line displays a d-orbital dependent renormalization along its trajectory in momentum space, thereby manifesting Hund's coupling. Our findings offer insights into the effect of electronic correlations on magnetic Dirac nodal lines, leading to an antiferromagnetic Hund nodal line. The interplay of magnetism, various symmetries and correlations can lead to intriguing physics in the solid state. Here, the authors report signatures of a Hund nodal line in the antiferromagnet YMn2Ge2. [ABSTRACT FROM AUTHOR]

By using the two distinct methods known as the exp (- ϕ (η)) and the E x p a -function methods, various forms of soliton solutions of the modified equal width wave equation (MEWE) with beta time derivative (BTD) are produced in this study. This model is used as a model in partial differential equations for the simulation of one-dimensional wave transmission in nonlinear media with dispersion processes. The obtained solutions are in the form of rational, trigonometry and hyperbolic trigonometry functions. Using Mathematica software, the resulting solitons are validated. Graphs are also used at the conclusion to explain the findings. These soliton solutions imply that these two methods are more dependable, simple and efficient than other methods. The findings can be used to explain how studious structures and other comparable non-linear physical structures are substantially understood. The obtained results are very helpful in the fields of optics, kinetics solid-state physics and hydro-magnetic waves in cold plasma. [ABSTRACT FROM AUTHOR]

Micro‐mechanical resonators are building blocks of a variety of applications in basic science and consumer electronics. This device technology is mainly based on well‐established and reproducible silicon‐based fabrication processes with outstanding performances in term of mechanical Q‐factor and sensitivity to external perturbations. Broadening the functionalities of micro‐electro‐mechanical systems (MEMS) by the integration of functional materials is a key step for both applied and fundamental science. However, combining functional materials with silicon‐based devices is challenging. An alternative approach is directly fabricating MEMS based on compounds inherently showing non‐trivial functional properties, such as transition metal oxides. Here, a full‐oxide approach is reported, where a high‐Tc$\rm {T_c}$ superconductor YBa2Cu3O7 (YBCO) is integrated with high Q‐factor micro‐bridge resonators made of single‐crystal LaAlO3 (LAO) thin films. LAO resonators are tensile strained, with a stress of about 350 MPa, show a Q‐factor above 200k, and have low roughness. YBCO overlayers are grown ex situ by pulsed laser deposition and YBCO/LAO bridges show zero resistance below 78 K and mechanical properties similar to those of bare LAO resonators. These results open new possibilities toward the development of advanced transducers, such as bolometers or magnetic field detectors, as well as experiments in solid state physics, material science, and quantum opto‐mechanics. [ABSTRACT FROM AUTHOR]

V2VI3-based materials are the best materials for thermoelectric cooling devices. Interest in studying the transport properties of V2VI3 thin films has increased after it was found that V2VI3 belong to the class of topological insulators. In this work, the dependences of electrical conductivity, Hall coefficient, charge carrier mobility on magnetic field and temperature of Bi2(Te0.9Se0.1)3 films with thicknesses 48 and 130 nm were measured and interpreted. The transport properties in the thin-film and bulk states were compared. The boundaries between weak and strong magnetic fields were determined. The obtained results are important for solid-state physics development and practical applications. [ABSTRACT FROM AUTHOR]

Modern solid-state physics increasingly focuses on the study of nanomaterials and the development of nanotechnologies. Various theoretical methods and research technologies are actively used to elucidate the significance of experimental results related to the study of solid-state defects. Progress in this field is likely associated with advancements in computer technologies and the development of modern quantum-chemical packages. The obtained spectra reveal a certain number of energy levels in the energy range from –30 to 20 eV. We determine the band structure, density of states, and total energy of NaF nanotubes with parameters (m, n), where m = 4, 5, 6, 8, and n = 1, 2, 3. The characteristics modeling is conducted using the Atomistix ToolKit software package and Virtual NanoLab program. This work presents the results of computer modeling of the density of states and total energy of NaF nanotubes within the framework of density functional theory. The obtained results allow classifying the tubular structures of NaF as quantum dots and contribute to further research into alkali metal halide crystals in nanostructures. [ABSTRACT FROM AUTHOR]

As is well known, Paul Drude put forward the very first quantitative theory of electrical conduction in metals in 1900. He could successfully account for the Wiedemann–Franz law which states that the ratio of thermal to electrical conductivity divided by temperature is a constant called the Lorenz number. As it turns out, in Drude's derivation there is a lucky cancellation of two errors. Drude's underestimatation (by an order of 100) of the value of square of the average electron velocity compensated for his overestimatation of the electronic heat capacity (by the same order of 100). This compensation or cancellation of two errors lead to a value of the Lorenz number very close to its experimental value; which is well known. There is another error of a factor of two which Drude made when he calculated two different relaxation times for heat conductivity and electrical conductivity; in this article we highlight how and why this error occurred in Drude's derivation and how it was removed 5 years later (in 1905) by Hendrik Lorentz when he used the Boltzmann equation and a single relaxation time. This article is of pedagogical value and may be useful to undergraduate/graduate students learning solid state physics. [ABSTRACT FROM AUTHOR]

Optical vortex array (OVA) containing multiple optical vortices is an optimal candidate for applications of optical communications, complex manipulation of multi-particle systems, and mass-synchronous fabrication. However, the existing OVAs have not been constructed to respond to the application requirements, particularly for micro-/nanomaterial fabrication where the boundary, size, and stability need to be carefully considered. To address this issue, we propose a Gibbs–Wulff OVA (GWOVA) by analogizing the Gibbs–Wulff theorem in solid-state physics. Herein, the Gibbs–Wulff theorem is first generalized to OVA's generation as the condition to confine its growth boundary. The GWOVA, which possesses versatile structures and arrangement modes (simple- and close-packed modes), is successfully generated and grown. It exhibits high stability and perfect symmetry during growth and rotation, which satisfies the symmetric group of D2s. Owing to its stable structure and growth boundary conditions, the GWOVA has great potential for a wide range of applications, particularly in micro-/nanomaterial fabrication. [ABSTRACT FROM AUTHOR]

The kagome lattice is an exciting solid state physics platform for the emergence of nontrivial quantum states driven by electronic correlations: topological effects, unconventional superconductivity, charge and spin density waves, and unusual magnetic states such as quantum spin liquids. While kagome lattices have been realized in complex multi-atomic bulk compounds, here we demonstrate from first-principles a process that we dub kagomerization, in which we fabricate a two-dimensional kagome lattice in monolayers of transition metals utilizing an hexagonal boron nitride (h-BN) overlayer. Surprisingly, h-BN induces a large rearrangement of the transition metal atoms supported on a fcc(111) heavy-metal surface. This reconstruction is found to be rather generic for this type of heterostructures and has a profound impact on the underlying magnetic properties, ultimately stabilizing various topological magnetic solitons such as skyrmions and bimerons. Our findings call for a reconsideration of h-BN as merely a passive capping layer, showing its potential for not only reconstructing the atomic structure of the underlying material, e.g. through the kagomerization of magnetic films, but also enabling electronic and magnetic phases that are highly sought for the next generation of device technologies. Using first-principles calculations, the authors highlight h-BN's role in reshaping transition metal monolayers into kagome lattices—a key structure in 2D physics—and in stabilizing topological solitons vital for advanced data storage solutions. [ABSTRACT FROM AUTHOR]

Definition: The Pandemic Equation describes multiple pandemic waves and has been applied to describe the COVID-19 pandemic. Using the generalized approaches of solid-state physics, we derive the Pandemic Equation, which accounts for the effects of pandemic mitigation measures and multiple pandemic waves. The Pandemic Equation uses slow and fast time scales for "curve flattening" and describing vaccination and mitigation measures and the Scaled Fermi–Dirac distribution functions for describing transitions between pandemic waves. The Pandemic Equation parameters extracted from the pandemic curves can be used for comparing different scenarios of the pandemic evolution and for extrapolating the pandemic evolution curves for the periods of time on the order of the instantaneous Pandemic Equation characteristic time constant. The parameter extraction for multiple locations could also allow for uncertainty quantification for such pandemic evolution predictions. [ABSTRACT FROM AUTHOR]

A comprehensive physical electro-thermal modeling approach is explored to investigate the intricate mechanisms underlying filament formation and the effect of surface perturbation in nanoscale Y2O3-based memristors. The approach integrates fundamental principles of solid-state physics, electrochemistry, and materials science to develop a detailed physical model that captures the key phenomena governing the operation of Y2O3 memristors. The simulation is carried out in a semiconductor physics-based tool, i.e., COMSOL Multiphysics with a defined MATLAB script, wherein simulation is based on the minimum free energy of the used materials at an applied input voltage. The fundamental processes in filament growth include ion migration, redox reactions, and vacancy dynamics within the Y2O3 lattice. Furthermore, the influence of surface perturbation on the overall device behavior, grain boundaries, and electrode interactions impact on memristor performance is also investigated. The surface perturbations significantly influenced the switching dynamics of the memristor, including variations in switching voltages, ON/OFF current ratio, filament radius, and filament temperature during the switching process. Therefore, the presented findings contribute to a deeper understanding of the physical mechanisms at play in Y2O3 memristors, offering valuable guidance for the design and engineering of these nanoscale devices for next-generation memory and neuromorphic computing applications. This physical modeling approach not only enhances our comprehension of memristor behavior but also paves the way for the development of more efficient and reliable memristor-based technologies. [ABSTRACT FROM AUTHOR]

Featured Application: The findings presented in this work will allow the calculation of the electronic density states as well as the electrical and optical properties of complex one-dimensional coupled periodic potential wells without using expensive licensed software. The analytical generalization for N periodic potential wells coupled to a probe rectangular-like potential and a zero potential is extremely important in the study of one-dimensional periodic potentials in solid state physics, e.g., in the calculation of transport, optical, and magnetic properties. These findings raise the possibility of calculating equations for the generalization of N arbitrary potentials related to any potential V (x) using special functions as a solution. In this work, a novel analytical generalization of the transcendental energy equation, group velocity, and effective mass for N-coupled potentials to a probe one-dimensional potential V = V (x) was proposed. Initially, two well-known linear periodic potentials V = V (x) were employed to obtain analytical solutions for rectangular-like and Dirac-delta potentials. Python libraries were used to easily represent the equations for one or two rectangular-like potentials coupled with an arbitrary potential, highlighting the transcendental energy, group velocity, and effective mass. The results showed that the group velocity behavior changed its orientation due to the sign of the potential, whereas the width of the potential V (x) strongly influenced the group velocity behavior. The effective mass was also modified by the potential shapes, and their combinations, both effective mass and group velocity, exhibited similar physical behaviors to those found in ordinary rectangular-like potentials. [ABSTRACT FROM AUTHOR]

In solid state physics, electronic properties of crystalline materials are often inferred from the spectrum of periodic Schrödinger operators. As a consequence of Bloch's theorem, the numerical computation of electronic quantities of interest involves computing derivatives or integrals over the Brillouin zone of so-called energy bands, which are piecewise smooth, Lipschitz continuous periodic functions obtained by solving a parametrized elliptic eigenvalue problem on a Hilbert space of periodic functions. Classical discretization strategies for resolving these eigenvalue problems produce approximate energy bands that are either non-periodic or discontinuous, both of which cause difficulty when computing numerical derivatives or employing numerical quadrature. In this article, we study an alternative discretization strategy based on an ad hoc operator modification approach. While specific instances of this approach have been proposed in the physics literature, we introduce here a systematic formulation of this operator modification approach. We derive a priori error estimates for the resulting energy bands and we show that these bands are periodic and can be made arbitrarily smooth (away from band crossings) by adjusting suitable parameters in the operator modification approach. Numerical experiments involving a toy model in 1D, graphene in 2D, and silicon in 3D validate our theoretical results and showcase the efficiency of the operator modification approach. [ABSTRACT FROM AUTHOR]

Textbooks often present the phenomenon of screening within the Thomas–Fermi model for three-dimensional free electron gases, but obtaining the dielectric response function and screening potential for dielectric systems of reduced dimensionality is also of pedagogical interest. In this work, we introduce a simple approach to investigate static screening in dielectric systems in the presence of an impurity charge for different dimensionalities. This approach is applicable to semiconductors and insulators alike. We demonstrate that, in 3D systems, the macroscopic dielectric function in reciprocal space is a constant, while in 2D and 1D systems, it strongly depends on the momentum transferred to the electrons in the dielectric. Through the proposed dielectric screening model, one can also determine binding energies in a hydrogenic model that can be used to describe excitations in real semiconductor systems. Screening in dielectrics is a measure of the strength of Coulomb interactions. Because of the reduced dimensionality, screening is hampered in 2D or quasi-1D materials, with important consequences in nanometer-scale systems that are currently important to the condensed matter community. This paper explains why reduced dimensionality reduces the screening. The topic is appropriate for undergraduate electromagnetism classes or advanced condensed matter courses. [ABSTRACT FROM AUTHOR]

Perovskites have long been materials of interest in solid‐state physics. Their structure leads them to exhibit various characteristics which have both theoretical and practical interest. Lattice dynamics can give a lot of insight into a material's nature such as phase transitions, thus the research presented here focuses on that, by doing a comprehensive vibrational and structural investigation of monocrystalline YAlO3 (YAP). Polarized Raman and infrared (IR) reflectance spectroscopy are used alongside ab initio and classical calculations. In the course of this work, complete Raman spectra have been obtained, confirming new vibrational modes, predicted by ab initio calculations but previously not observed experimentally. IR reflectance spectra have been obtained for the first time for this material. Classical molecular dynamics has been employed to calculate the phonon dispersion and density of states. [ABSTRACT FROM AUTHOR]

Perovskites have long been materials of interest in solid‐state physics. Their structure leads them to exhibit various characteristics which have both theoretical and practical interest. Lattice dynamics can give a lot of insight into a material's nature such as phase transitions, thus the research presented here focuses on that, by doing a comprehensive vibrational and structural investigation of monocrystalline YAlO3 (YAP). Polarized Raman and infrared (IR) reflectance spectroscopy are used alongside ab initio and classical calculations. In the course of this work, complete Raman spectra have been obtained, confirming new vibrational modes, predicted by ab initio calculations but previously not observed experimentally. IR reflectance spectra have been obtained for the first time for this material. Classical molecular dynamics has been employed to calculate the phonon dispersion and density of states. [ABSTRACT FROM AUTHOR]

SUMMARY OF COVERED AREAS Several articles in this special topics issue focus on the location of solid-fluid phase equilibria lines, using either simulation,[[17], [19], [21], [23]] theoretical,[21] or experimental methods.[24] Knowledge of coexistence lines is obviously interesting on its own right, but several articles highlight other reasons why precise knowledge of phase equilibria is relevant. Obtaining a deep knowledge of the behavior of condensed phases (solids, liquids, and amorphous) is a great challenge. This challenge is compounded in studies in which two or more phases need to be described simultaneously, for example, in the characterization of solid-liquid interfaces or the prediction of solid-liquid phase equilibrium. [Extracted from the article]

Charge density waves (CDWs) involved with electronic and phononic subsystems simultaneously are a common quantum state in solid-state physics, especially in low-dimensional materials. However, CDW phase dynamics in various dimensions are yet to be studied, and their phase transition mechanism is currently moot. Here we show that using the distinct temperature evolution of orientation-dependent ultrafast electron and phonon dynamics, different dimensional CDW phases are verified in CuTe. When the temperature decreases, the shrinking of c-axis length accompanied with the appearance of interchain and interlayer interactions causes the quantum fluctuations (QF) of the CDW phase until 220 K. At T < 220 K, the CDWs on the different ab-planes are finally locked with each other in anti-phase to form a CDW phase along the c-axis. This study shows the dimension evolution of CDW phases in one CDW system and their stabilized mechanisms in different temperature regimes. Some materials host multiple charge density wave states, however, their dynamics and the nature of phase transitions are often unclear. Here, using temperature and orientation resolved ultrafast spectroscopy, the authors reveal charge density waves of different dimensionality in CuTe and elucidate their mechanism. [ABSTRACT FROM AUTHOR]

The document titled "Advanced Inorganic Semiconductor Materials" is a summary of a special issue that explores current research and ideas in the field of inorganic semiconductors. The issue includes nine articles and two topical reviews that cover various topics, such as 2D materials, quantum dots, avalanche photodiodes, and perovskites. Each article delves into different aspects of these materials, including their optical, mechanical, and electronic properties, as well as their potential applications in optoelectronic devices. The findings presented in the articles contribute to the understanding and development of advanced inorganic semiconductor materials for various applications. The document expresses gratitude to the contributors and reviewers for their valuable contributions to the special issue. [Extracted from the article]

I describe aspects of my life in physics: the name I publish under, great physicists I have known, how I got into quantum foundations, what role I've played in it. My form is autobiographical, but my personal experience may illustrate what it was like being a physicist over the past sixty years. I offer some offbeat ways of thinking about some orthodox physics. [ABSTRACT FROM AUTHOR]

The solution of a quantum periodic potential in solid state physics is relevant because one can understand how electrons behave in a corresponding crystal. In this paper, the analytical solution of the energy formulation for a one-dimensional periodic potential that meets certain boundary conditions is developed in a didactic and detailed way. In turn, the group speed and effective mass are also calculated from the transcendental energy equation of a potential V = V (x) . From this, a comparison is made with periodic potentials with known analytical solutions, such as the Dirac delta, as well as rectangular and triangular potentials. Finally, some limits are proposed in which these periodic potentials of the form V = V (x) approach the periodic Dirac delta potential of positive intensity. Therefore, the calculations described in this paper can be used as the basis for more-complex one-dimensional potentials and related simulations. [ABSTRACT FROM AUTHOR]

Specific properties of quantum field theory are described by considering the combination of the system under investigation and the cloud of virtual or real particles associated with the field. Such a structure is called a "dressed system", in contrast with the bare one in the absence of the interaction with the field. The description of the properties of such clouds in various physical situations is, today, an active research area. Here, we present the main features associated with virtual and real dressings, focusing on photon dressing. In analogy to virtual photon clouds dressing electrons in vacuum, virtual phonon clouds appear in solid-state physics. The interaction between real photons and the schematized two-level structure of an atom paves the way to flexible quantum control. Here, a unifying Floquet engineering approach is applied to describe single- and multiple-dressed atom configurations. Connections with the past and present atomic physics experiments are presented. [ABSTRACT FROM AUTHOR]

Solid-state physics has important applications in the development of modern technologies. Although solid-state concepts, such as electric and thermal conductivity, are included in the curricula at all educational levels, even university students have many incorrect ideas about them. The incorrect ideas identified in previous studies are mainly related to macroscopic aspects of solid-state physics. With the aim of gaining a more comprehensive insight into students' understanding of solid-state physics, we have developed a multiple-choice concept inventory on microscopic models of electric and thermal conductivity of solids (METCS). The inventory has been field-tested with a sample consisting of 233 first-year medical faculty and engineering students from the University of Rijeka (Croatia). METCS proved to have good psychometric features and it helped to uncover many incorrect ideas that have not been reported in the earlier physics education literature. The findings from this study could be a good starting point for the development of evidence-based, university-level tutorials on microscopic models of electric and thermal conductivity. [ABSTRACT FROM AUTHOR]

This document is an editorial introducing a special issue of the journal Magnetochemistry. The special issue focuses on research related to magnetic and magnetoelectric materials. The editorial acknowledges the contributions of various authors and their research topics, including investigations of thin films, superconductors, nanocomposites, and spinel compounds. The authors express gratitude to the editorial team and declare no conflicts of interest. [Extracted from the article]

In the current research, we consider the solution of dispersion relations addressed to solid state physics by using artificial neural networks (ANNs). Most specifically, in a double semiconductor heterostructure, we theoretically investigate the dispersion relations of the interface polariton (IP) modes and describe the reststrahlen frequency bands between the frequencies of the transverse and longitudinal optical phonons. The numerical results obtained by the aforementioned methods are in agreement with the results obtained by the recently published literature. Two methods were used to train the neural network: a hybrid genetic algorithm and a modified version of the well-known particle swarm optimization method. [ABSTRACT FROM AUTHOR]

In this study, carbon fiber reinforced polymer matrix composites were produced to investigate the trigger effect on energy absorption performance. Production was carried out by vacuum infusion method. Three types of trigger geometry were opened on the composite crash boxes produced and also comparison sample without trigger was prepared. The quasi-static compression tests of these four different samples were carried out and the energy absorption performances of the samples were evaluated with the obtained data. In addition, the damages of the samples were examined, and it was revealed how they changed with the trigger. Accordingly, the sample described as S-2, (the triggered sample, which consists of four symmetrical slits downwards from its upper surface) exhibited the best performance in terms of absorbed energy. Additionally, the peak forces were reduced with the triggers opened and the maximum peak force decreases were seen in S-3(with hole type triggers) and S-4 (with horizontal slit type triggers) samples. [ABSTRACT FROM AUTHOR]

This review is devoted to one of the most interesting and actively developing fields in condensed matter physics—theory of topological insulators. Apart from its importance for theoretical physics, this theory enjoys numerous connections with modern mathematics, in particular, with topology and homotopy theory, Clifford algebras, K-theory and non-commutative geometry. From the physical point of view topological invariance is equivalent to adiabatic stability. Topological insulators are characterized by the broad energy gap, stable under small deformations, which motivates application of topological methods. A key role in the study of topological objects in the solid state physics is played by their symmetry groups. There are three main types of symmetries—time reversion symmetry, preservation of the number of particles (charge symmetry) and PH-symmetry (particle-hole symmetry). Based on the study of symmetry groups and representation theory of Clifford algebras Kitaev proposed a classification of topological objects in solid state physics. In this review we pay special attention to the topological insulators invariant under time reversion. [ABSTRACT FROM AUTHOR]

A crucial step in developing new and/or more efficient devices relies on the detailed knowledge of the properties of their main (elemental or combined) parts. The same applies to titanium dioxide TiO2 that forms the basis of today numerous applications whose performances are determined by the presence or relative amount of the Anatase (A-) and Rutile (R-) most common phases of TiO2. Whereas the basic structural characteristics of these two polymorphs are very well-established, some of their optical aspects still deserve attention. With these ideas in mind this work presents a comprehensive investigation of the optical bandgap Egap of TiO2 under the Anatase and Rutile phases. The study considered pure A-TiO2 and R-TiO2 samples in the form of powder, and optical reflectance and Raman spectroscopy in the 83–823 K temperature range. In addition to reliable Egap values the study explores their temperature-dependent Egap(T) behavior that is expected to assist future advancements in the field of TiO2-based materials and devices (thin films, interfaces, low-dimensional systems, and photocatalytic and solar cells, for example).

There are opportunities for the application of chemical physics style thinking to models central to solid state physics. Solid state physics has largely been left to its own devices by the chemical physics theory community, which is a shame. I will show here that cross fertilization of ideas is real and beneficial to science. This essay is written with the hope of encouraging young theorists with a chemical physics background to enter this rich and promising area. There are many low hanging fruit available essentially because condensed matter physics traditions, models, and standards for progress are so much different than in chemical physics. By way of a warning label, right now neither community is supporting this endeavor. I am hoping this article will help, a little. I make the apology for using mainly (but not exclusively) my own narrow experience and contributions to illustrate this essay. I understand it is only a small piece of the pie, but I do believe the message here is larger: a chemical physics mindset is complementary to the condensed matter physics mindset, and they would work best together. [ABSTRACT FROM AUTHOR]

The article focuses on the Nobel Prize in Chemistry 2023 awarded to Aleksey Yekimov, Louis E. Brus, and Moungi G. Bawendi for their discovery and synthesis of quantum dots. Topics include the history of quantum size effects, the pioneering experiments in the 1970s, the independent work of Yekimov and Brus in the 1980s, and the subsequent breakthroughs by Bawendi in the 1990s, leading to the widespread applications of quantum dots in scientific research and commercial products.

This paper concerns the homogenization of Schrödinger equations for non-crystalline matter, that is to say the coefficients are given by the composition of stationary functions with stochastic deformations. Two rigorous results of so-called effective mass theorems in solid state physics are obtained: a general abstract result (beyond the classical stationary ergodic setting), and one for quasi-perfect materials (i.e. the disorder in the non-crystalline matter is limited). The former relies on the double-scale limits and the wave function is spanned on the Bloch basis. Therefore, we have extended the Bloch Theory which was restricted until now to crystals (periodic setting). The second result relies on the Perturbation Theory and a special case of stochastic deformations, namely stochastic perturbation of the identity. [ABSTRACT FROM AUTHOR]

The well-established and rapidly expanding field of molecular processes in excited systems, facilitated by the use of light sources, garners significant research interest from numerous experimental and theoretical groups worldwide. This highly interdisciplinary field establishes extensive connections with atomic, molecular and optical physics, astrophysics, biophysics, physical chemistry, solid-state physics and even molecular biology. The present topic provides an advanced overview of research activities in cutting-edge areas such as ultrafast lasers, nanoscale systems, atomic and molecule collisions on surfaces and molecular photofragmentation processes. The contributions to this subject encompass experimental, theoretical and computational studies conducted both at the fundamental level, exploring elementary mechanisms, and at a more applied level, addressing the requirements of diverse applications in nanotechnology and materials science. [ABSTRACT FROM AUTHOR]

Peierls transition that modifies electronic band structure has attracted intensive attention in solid state physics. In the present work, we report that a photonic analog of Peierls transition has been observed in a 1-D triangular metal diaphragm array, where the photonic bandgap structures have been designed at will by adjusting periodically metal diaphragm positions. It is shown by the numerical analysis that the transmission and radiation effect of the present periodic metal structure designed through the Peierls transition rule exhibits the behavior significantly different from an original periodic structure with each unit cell containing a metal diaphragm. The near- and far-field measurement results are in good agreement with our theoretical simulation. The present effect of photonic Peierls transition can serve as a working mechanism for designing new types of guided wave devices. It can be seen that the photonic Peierls transition would be one of the simplest ways for modifying the transport characteristics of electromagnetic waves in periodic structures. [ABSTRACT FROM AUTHOR]

Tavis-Cummings (TC) cavity quantum electrodynamical effects, describing the interaction of N atoms with an optical resonator, are at the core of atomic, optical and solid state physics. The full numerical simulation of TC dynamics scales exponentially with the number of atoms. By restricting the open quantum system to a single excitation, typical of experimental realizations in quantum optics, we analytically solve the TC model with an arbitrary number of atoms with linear complexity. This solution allows us to devise the Quantum Mapping Algorithm of Resonator Interaction with N Atoms (Q-MARINA), an intuitive TC mapping to a quantum circuit with linear space and time scaling, whose N+1 qubits represent atoms and a lossy cavity, while the dynamics is encoded through 2N entangling gates. Finally, we benchmark the robustness of the algorithm on a quantum simulator and superconducting quantum processors against the quantum master equation solution on a classical computer. [ABSTRACT FROM AUTHOR]

The quantum Hall effect is one of the most extensively studied topological effects in solid‐state physics. The transitions between different quantum Hall states exhibit critical phenomena described by universal critical exponents. Numerous numerical finite size scaling studies have focused on the critical exponent ν for the correlation length. In such studies, it is important to take proper account of irrelevant corrections to scaling. Recently, Dresselhaus et al. proposed a new scaling ansatz, which they applied to the two terminal conductance of the Chalker–Coddington model. Herein, their proposal is applied to the previously reported data for the Lyapunov exponents of that model using both polynomial fitting and Gaussian process fitting. [ABSTRACT FROM AUTHOR]

The interest in RBa2Cu3O7–δ (R = lanthanides) stems from its superconducting properties. These represent a very significant advance in solid-state materials physics and have been extensively studied for decades, with the aim of increasing the critical temperature by doping or external parameters such as pressure. In the present review, we briefly discuss oxygen diffusion in RBa2Cu3O7–δ with respect to its composition. We consider related compounds as a comparison. [ABSTRACT FROM AUTHOR]

We consider a connection problem of the first Painlev\'e equation (PI), trying to connect the local behavior (Laurent series) near poles and the asymptotic behavior as the variable t tends to the negative infinity for real PI functions. We get a classification of the real PI functions in terms of (p, H) so that they behave differently at the negative infinity, where p is the location of a pole and H is the free parameter in the Laurent series. Some limiting-form connection formulas of PI functions are obtained for large H. Specifically, for the real tritronqu\'ee solution, the large-n asymptotic formulas of pn and Hn are obtained, where pn is the nth pole on the real line in the ascending order and Hn is the associated free parameter. Our approach is based on the complex WKB method (also known as the method of uniform asymptotics) introduced by Bassom et al. in their study on the connection problem of the second Painlev\'e transcendent [Arch. Ration. Mech. Anal., 143 (1998), pp. 241--271]. Several numerical simulations are carried out to verify our main results. Meanwhile, we obtain the phase diagram of P\I solutions in the (p, H) plane, which somewhat resembles the Brillouin zones in solid-state physics. The asymptotic and numerical results obtained in this paper partially answer Clarkson's open question on the connection problem of the first Painlev\'e transcendent. [ABSTRACT FROM AUTHOR]

Professor Sergey Alekseevich Pikin, a renowned theoretical physicist, passed away at the age of 82. He made significant contributions to condensed matter physics, specifically in the field of liquid crystals. His research focused on various aspects of liquid crystals, including structural phase transitions, electro-hydrodynamics, orientational turbulence, and thermodynamics. Professor Pikin collaborated with experimental colleagues, published a monograph on structural transformations in liquid crystals, and developed theories on flexoelectricity, phase transitions in chiral smectics C, molecular motors, and multiferroics. He was highly respected by his peers and will be greatly missed by the scientific community. Additionally, Professor Pikin had a deep appreciation for his family, art, and music. [Extracted from the article]

Introduction/purpose: Quantum field theory techniques are able to describe precisely, inter alia, collective phenomena of statistical and solid state physics. Method: The path integral method with a Wick rotation shows its complete analogy with the partition function of statistical mechanics. Results: The Landau–Ginzburg phenomenology successfully describes collective phenomena such as spontaneous magnetization and superconductivity. Conclusions: Symmetry breaking phenomena could give macroscopic results. [ABSTRACT FROM AUTHOR]

Introductory textbooks in solid state physics present solvable models for illustrating the occurrence of allowed bands and forbidden gaps in the energy spectrum of Bloch electrons. However, the quantum mechanical description of electrons in non-periodic solids, such as amorphous materials, is beyond the scope of introductory courses because of its intrinsic complexity. The tight-binding approximation can account for such a scenario by letting the atomic levels vary at random from lattice site to site. We theoretically tackle the study of the average properties of the energy spectrum by introducing a transfer matrix method that allows us to obtain closed expressions for the so-called coherent potential. The coherent potential is energy-dependent and constant in space. It replaces the actual atomic random potential, thus generating a periodic effective medium with the same average properties as the non-periodic solid. We demonstrate that the average density of states can be calculated within this framework without relying on heavy mathematical machinery. Thus, our approach is suitable for introductory courses in solid state physics and materials science. [ABSTRACT FROM AUTHOR]

Polar sea ice is a critical component of Earth's climate system. As a material, it is a multiscale composite of pure ice with temperature-dependent millimeter-scale brine inclusions, and centimeter-scale polycrystalline microstructure which is largely determined by how the ice was formed. The surface layer of the polar oceans can be viewed as a granular composite of ice floes in a sea water host, with floe sizes ranging from centimeters to tens of kilometers. A principal challenge in modeling sea ice and its role in climate is how to use information on smaller-scale structures to find the effective or homogenized properties on larger scales relevant to process studies and coarse-grained climate models. That is, how do you predict macroscopic behavior from microscopic laws, like in statistical mechanics and solid state physics? Also of great interest in climate science is the inverse problem of recovering parameters controlling small-scale processes from large-scale observations. Motivated by sea ice remote sensing, the analytic continuation method for obtaining rigorous bounds on the homogenized coefficients of two-phase composites was applied to the complex permittivity of sea ice, which is a Stieltjes function of the ratio of the permittivities of ice and brine. Integral representations for the effective parameters distill the complexities of the composite microgeometry into the spectral properties of a self-adjoint operator like the Hamiltonian in quantum physics. These techniques have been extended to polycrystalline materials, advection diffusion processes, and ocean waves in the sea ice cover. Here we discuss this powerful approach in homogenization, highlighting the spectral representations and resolvent structure of the fields that are shared by the two-component theory and its extensions. Spectral analysis of sea ice structures leads to a random matrix theory picture of percolation processes in composites, establishing parallels to Anderson localization and semiconductor physics and providing new insights into the physics of sea ice. [ABSTRACT FROM AUTHOR]

Due to the increasing number of internal combustion engine vehicles, fossil fuel sources have decreased drastically in the last century. In addition, the concerns about global warming caused by vehicle emissions have led automotive manufacturers to search for new alternatives to transport. Quadricycles have started to be seen as future transport vehicles due to their smaller design and lower energy consumption when compared to conventional vehicles. Furthermore, they are also considered to prevent increasing traffic jams in metropolitan areas. The lightweight design of a quadricycle is crucial since its weight would affect energy consumption. On the other hand, because of their minimalistic design, crashworthiness is another factor that must be considered in the structural design of quadricycles for the safety of occupants in case of a collision. Composites are one of the most promising materials for manufacturing lightweight structures due to having a high strength-to-weight ratio compared to conventional metals. In this study, different body designs and optimizations of quadricycles are introduced. Comparisons are made between conventional metals and composite materials used in quadricycles in terms of weight and stiffness. Studies showed that a 15% increase in specific energy absorption capability and a 50% weight reduction at the same time is possible by using composite materials rather than metals in the design of structural parts. [ABSTRACT FROM AUTHOR]