Condensed Matter

11 pages, 5696 KiB

Open AccessArticle

Structure and Properties of (Fe₈₀Ga₂₀)_99.8Ce_0.2 Alloy in Cast and Hot Rolled State

by Vasily Milyutin, Irina Gervasyeva, Azambek Kalonov, Denis Shishkin, Denis Davydov and Liudmila Stashkova

Condens. Matter 2025, 10(1), 8; https://doi.org/10.3390/condmat10010008 - 30 Jan 2025

Abstract

FeGa alloys with small additions of rare-earth elements surpass binary alloys in magnetostriction and plasticity. For this reason, they are considered promising magnetostrictive materials for various electrical engineering applications. The alloy (Fe₈₁Ga₁₉)_99.8Ce_0.2 was prepared and investigated [...] Read more.

FeGa alloys with small additions of rare-earth elements surpass binary alloys in magnetostriction and plasticity. For this reason, they are considered promising magnetostrictive materials for various electrical engineering applications. The alloy (Fe₈₁Ga₁₉)_99.8Ce_0.2 was prepared and investigated in this work. It was found that in the cast state, it has a magnetostriction of 3/2 λ about 100 ppm, saturation magnetization of 150 emu/g, tensile strength of about 300 MPa, and fracture strain of 3%. The microstructure, crystallographic texture, and behavior when heated of the alloy were investigated. Then the ingot was subjected to forging and hot rolling with a deformation degree of 90% at 1000 °C. The structure and mechanical properties of samples cut from a hot rolling sheet were studied. Their tensile strength and fracture strain increase compared to cast state up to 600 MPa and 4% correspondingly. Full article

► Show Figures

Figure 1

11 pages, 826 KiB

Open AccessArticle

Density Collective Modes of Exciton Superfluidity in Bilayer Systems

by Filippo Pascucci, Sara Conti, David Neilson, Andrea Perali and Jacques Tempere

Condens. Matter 2025, 10(1), 7; https://doi.org/10.3390/condmat10010007 - 16 Jan 2025

Abstract

We propose a new way to establish the existence of a superfluid phase in an exciton bilayer system by exploiting the properties of its collective modes. We focus on the density collective modes and treat them within Random Phase Approximation. By comparing results [...] Read more.

We propose a new way to establish the existence of a superfluid phase in an exciton bilayer system by exploiting the properties of its collective modes. We focus on the density collective modes and treat them within Random Phase Approximation. By comparing results for the normal and superfluid states, we are able to identify unambiguous fingerprints of the exciton superfluid phase. We compare the collective modes of the exciton system and cold atom systems, and we discuss the collective modes of the exciton superfluid order parameter. Full article

(This article belongs to the Special Issue Fluctuations and Highly Non-linear Phenomena in Superfluids and Superconductors VIII)

► Show Figures

Figure 1

11 pages, 4413 KiB

Open AccessArticle

Crystal Structure Evolution of Piezoelectric Fe-Doped ZnO Film by Magnetron Co-Sputtering Technique

by Ya-Chih Cheng, Sanjaya Brahma, Sean Wu, Jow-Lay Huang and Alex C. H. Lee

Condens. Matter 2025, 10(1), 6; https://doi.org/10.3390/condmat10010006 - 15 Jan 2025

Abstract

Zinc oxide (ZnO) exhibits piezoelectric properties due to its asymmetric structure, making it suitable for piezoelectric devices. This experiment deposited Fe-doped ZnO films on silicon substrates using a dual-target magnetron co-sputtering system. The films achieved a high c-axis orientation, and the piezoelectric coefficient [...] Read more.

Zinc oxide (ZnO) exhibits piezoelectric properties due to its asymmetric structure, making it suitable for piezoelectric devices. This experiment deposited Fe-doped ZnO films on silicon substrates using a dual-target magnetron co-sputtering system. The films achieved a high c-axis orientation, and the piezoelectric coefficient of the film reached its optimal value of 44.35 pC/N when doped with 0.5 at% of Fe. This value is approximately three times that of undoped ZnO films with a piezoelectric coefficient of 13.04 pC/N. The study utilized a diffractometer, scanning electron microscopy, transmission electron microscopy, and atomic force microscopy to evaluate the crystal structure evolution of the zinc oxide films and employed X-ray photoelectron spectroscopy to assess the valence state of the Fe ions. Full article

► Show Figures

Figure 1

20 pages, 12787 KiB

Open AccessArticle

Exploring the Properties of Quantum Scars in a Toy Model

by Sudip Sinha and Subhasis Sinha

Condens. Matter 2025, 10(1), 5; https://doi.org/10.3390/condmat10010005 - 12 Jan 2025

Abstract

We introduce the concept of ergodicity and explore its deviation caused by quantum scars in an isolated quantum system, employing a pedagogical approach based on a toy model. Quantum scars, originally identified as traces of classically unstable orbits in certain wavefunctions of chaotic [...] Read more.

We introduce the concept of ergodicity and explore its deviation caused by quantum scars in an isolated quantum system, employing a pedagogical approach based on a toy model. Quantum scars, originally identified as traces of classically unstable orbits in certain wavefunctions of chaotic systems, have recently regained interest for their role in non-ergodic dynamics, as they retain memory of their initial states. We elucidate these features of quantum scars within the same framework of this toy model. The integrable part of the model consists of two large spins, with a classical counterpart, which we combine with a random matrix to induce ergodic behavior. Scarred states can be selectively generated from the integrable spin Hamiltonian by protecting them from the ergodic states using a projector method. Deformed projectors mimic the ‘quantum leakage’ of scarred states, enabling tunable mixing with ergodic states and thereby controlling the degree of scarring. In this simple model, we investigate various properties of quantum scarring and shed light on different aspects of many-body quantum scars observed in more complex quantum systems. Notably, the underlying classicality can be revealed through the entanglement spectrum and the dynamics of ‘out-of-time-ordered correlators’. Full article

(This article belongs to the Special Issue Non-equilibrium Dynamics in Ultra-Cold Quantum Gases)

► Show Figures

Figure 1

16 pages, 326 KiB

Open AccessArticle

Quantum Kinetic Theory of the Spin Hall Effect for Disordered Graphene with Rashba Spin–Orbit Coupling

by Roberto Raimondi and Thierry Valet

Condens. Matter 2025, 10(1), 4; https://doi.org/10.3390/condmat10010004 - 6 Jan 2025

Abstract

The spin Hall effect for the model Hamiltonian of graphene with Rashba spin–orbit coupling is analyzed by means of a recently derived quantum kinetic theory of the linear response for multi-band electron systems. The latter expresses the interband part of the density matrix [...] Read more.

The spin Hall effect for the model Hamiltonian of graphene with Rashba spin–orbit coupling is analyzed by means of a recently derived quantum kinetic theory of the linear response for multi-band electron systems. The latter expresses the interband part of the density matrix in terms of the intraband occupation numbers, which can be obtained as solutions of a Boltzmann transport equation. The analysis, which, in the case of the model here considered, can be carried out in a completely analytical way, thus provides an effective pedagogical illustration of the general theory. While our results agree with those previously obtained with alternative approaches for the same model, our comparatively simpler and more physically transparent derivation illustrates the advantages of our formalism when dealing with non trivial multi-band Hamiltonians. Full article

(This article belongs to the Special Issue Fluctuations and Highly Non-linear Phenomena in Superfluids and Superconductors VIII)

► Show Figures

Figure 1

23 pages, 6551 KiB

Open AccessFeature PaperArticle

Anomalous Polarization in One-Dimensional Aperiodic Insulators

by Anouar Moustaj, Julius Krebbekx and Cristiane Morais Smith

Condens. Matter 2025, 10(1), 3; https://doi.org/10.3390/condmat10010003 - 6 Jan 2025

Abstract

Multilevel charge pumping is a feature that was recently observed in quasiperiodic systems. In this work, we show that it is more generic and appears in different aperiodic systems. Additionally, we show that for aperiodic systems admitting arbitrarily long palindromic factors, the charge [...] Read more.

Multilevel charge pumping is a feature that was recently observed in quasiperiodic systems. In this work, we show that it is more generic and appears in different aperiodic systems. Additionally, we show that for aperiodic systems admitting arbitrarily long palindromic factors, the charge pumping protocol connects two topologically distinct insulating phases. This confirms the existence of topological phases in aperiodic systems whenever their finite-size realizations admit inversion symmetry. These phases are characterized by an anomalous edge response resulting from the bulk–boundary correspondence. We show that these signatures are all present in various chains, each representing a different class of structural aperiodicity: the Fibonacci quasicrystal, the Tribonacci quasicrystal, and the Thue–Morse chain. More specifically, we calculate three quantities: the Berry phase of the periodic approximation of the finite-size systems, the polarization response to an infinitesimal static and constant electric field in systems with open boundary conditions, and the degeneracy of the entanglement spectrum. We find that all of them provide signatures of a topologically nontrivial phase. Full article

(This article belongs to the Section Condensed Matter Theory)

► Show Figures

Figure 1

8 pages, 4625 KiB

Open AccessArticle

Topological Superconductivity of the Unconventional Type, S = 1, S^z = 0, in a Layer of Adatoms

by Edine Silva and Mucio A. Continentino

Condens. Matter 2025, 10(1), 2; https://doi.org/10.3390/condmat10010002 - 5 Jan 2025

Abstract

In this paper, we study the appearance of topological p-wave superconductivity of the type

S = 1

,

S^{z} = 0

in a layer of adatoms. This unconventional superconductivity arises due to an anti-symmetric hybridization between the orbitals of the adatoms [...] Read more.

In this paper, we study the appearance of topological p-wave superconductivity of the type

S = 1

,

S^{z} = 0

in a layer of adatoms. This unconventional superconductivity arises due to an anti-symmetric hybridization between the orbitals of the adatoms and those of the atoms in the superconducting BCS substrate. This two-dimensional system is topologically non-trivial only in the absence of a magnetic field and belongs to class DIII of the Altland–Zirnbauer classification. We obtain the Pfaffian that characterizes the topological phases of the system and its phase diagram. We discuss the differences between the two-dimensional case and a chain with the same type of superconductivity. Full article

(This article belongs to the Special Issue Superstripes Physics, 3rd Edition)

► Show Figures

Figure 1

11 pages, 4730 KiB

Open AccessArticle

Terahertz Time-Domain Spectroscopy of Substituted Gadolinium Gallium Garnet

by Ke Wang, Junchao Xu, Hironaru Murakami, Hiroyasu Yamahara, Munetoshi Seki, Hitoshi Tabata and Masayoshi Tonouchi

Condens. Matter 2025, 10(1), 1; https://doi.org/10.3390/condmat10010001 - 25 Dec 2024

Abstract

Temperature dependence of the lowest frequency transverse optical phonon (TO1) in a single crystal Substituted Gadolinium Gallium Garnet (SGGG, (001)) was studied using terahertz time-domain spectroscopy at temperatures between 80 K and 500 K. The complex dielectric constants were calculated from the optical [...] Read more.

Temperature dependence of the lowest frequency transverse optical phonon (TO1) in a single crystal Substituted Gadolinium Gallium Garnet (SGGG, (001)) was studied using terahertz time-domain spectroscopy at temperatures between 80 K and 500 K. The complex dielectric constants were calculated from the optical constants fitting with the Lorentz oscillator model. The results show that the TO1 phonon of SGGG is at 2.5 THz at room temperature, the frequency of the TO1 phonon slightly decreases, and the dumping factor clearly increases with increasing temperature. Additionally, our results demonstrate that even a small substitution can induce a phonon shift, leading to higher absorption and causing a slight degradation in thermal stability. Our work is expected to support the development of magneto-optical and spintronic devices. Full article

► Show Figures

Figure 1

15 pages, 1834 KiB

Open AccessReview

Multiband Superconductivity, Polarons, Jahn-Teller Polarons, Heterogeneity, and High-Temperature Superconductivity

by Annette Bussmann-Holder and Hugo Keller

Condens. Matter 2024, 9(4), 56; https://doi.org/10.3390/condmat9040056 - 19 Dec 2024

Abstract

Early on, oxides were ruled out from superconductivity, since they are typically large-band-gap insulators. Nevertheless, a rather small number of them were found to be superconducting, with transition temperatures up to 14 K and a remarkably low carrier density. This was the starting [...] Read more.

Early on, oxides were ruled out from superconductivity, since they are typically large-band-gap insulators. Nevertheless, a rather small number of them were found to be superconducting, with transition temperatures up to 14 K and a remarkably low carrier density. This was the starting point of K. Alex Müller (KAM) becoming interested in superconductivity in oxides. Step by step, he advanced the research on oxides and finally discovered, together with J. Georg Bednorz, high-temperature superconductivity (HTSC) in the perovskite-type compound Ba-La-Cu-O. Even though he was inspired by specific and clear ideas in his search, he added new impact in the understanding of HTSC for many years after receipt of the Nobel prize for this discovery. Full article

(This article belongs to the Special Issue Superstripes Physics, 3rd Edition)

► Show Figures

Figure 1

14 pages, 1835 KiB

Open AccessArticle

Magnetic and Electronic Inhomogeneity in Sm_1−xEu_xB₆

by M. Victoria Ale Crivillero, Priscila F. S. Rosa, Zachary Fisk, Jens Müller, Pedro Schlottmann and Steffen Wirth

Condens. Matter 2024, 9(4), 55; https://doi.org/10.3390/condmat9040055 - 13 Dec 2024

Abstract

While SmB₆ attracts attention as a possible topological Kondo insulator, EuB₆ is known to host magnetic polarons that give rise to large magnetoresistive effects above its ferromagnetic order transition. Here, we investigate single crystals of Sm_1−xEu_xB₆ [...] Read more.

While SmB₆ attracts attention as a possible topological Kondo insulator, EuB₆ is known to host magnetic polarons that give rise to large magnetoresistive effects above its ferromagnetic order transition. Here, we investigate single crystals of Sm_1−xEu_xB₆ by magnetic and magnetotransport measurements to explore a possible interplay of these two intriguing phenomena, with a focus on the Eu-rich substitutions. Sm_0.01Eu_0.99B₆ exhibits generally similar behavior as EuB₆. Interestingly, Sm_0.05Eu_0.95B₆ combines a global antiferromagnetic order with local polaron formation. A pronounced hysteresis is found in the magnetoresistance of Sm_0.1Eu_0.9B₆ at low temperature (

T =

1.9 K) and applied magnetic fields between 2.3 and 3.6 T. The latter is in agreement with a phenomenological model that predicts the stabilization of ferromagnetic polarons with an increasing magnetic field within materials with a global antiferromagnetic order. Full article

(This article belongs to the Special Issue Superstripes Physics, 3rd Edition)

► Show Figures

Figure 1

14 pages, 1630 KiB

Open AccessArticle

Dielectric Response of Yttria–Zirconia Ordered Solids Within Density-Functional Theory in the Random-Phase Approximation

by A. G. Marinopoulos

Condens. Matter 2024, 9(4), 54; https://doi.org/10.3390/condmat9040054 - 10 Dec 2024

Abstract

Despite the fact that yttria-stabilized zirconia has been studied experimentally by optical and electron energy-loss spectroscopies, a first-principles theoretical interpretation of the dielectric response and electronic excitations is still lacking. The present study reports calculations of the complex dielectric function, reflectivity spectrum and [...] Read more.

Despite the fact that yttria-stabilized zirconia has been studied experimentally by optical and electron energy-loss spectroscopies, a first-principles theoretical interpretation of the dielectric response and electronic excitations is still lacking. The present study reports calculations of the complex dielectric function, reflectivity spectrum and electron energy-loss function of two ordered yttria–zirconia compounds: Zr₆Y₂O₁₅ and Zr₃Y₄O₁₂. The adopted methodology is based on linear-response theory with a semilocal density functional and the random-phase approximation including local-field effects. Comparisons with existing experimental data show an acceptable agreement showcasing how the different yttria content affects dielectric properties and spectra lineshapes. Strong discrepancies with experimental data are mainly confined to the low-energy part of the optical spectra and concern both the peak positions and the lineshape intensities. The onset of the optical absorption is considerably underestimated from the calculations owing to the well-known deficiency of semilocal density functionals to describe the quasiparticle band gaps. The energy-loss spectra, instead, are reproduced extremely well provided that local-field effects are included in the response functions. These effects are particularly important for the description of the semicore Zr–4p and Y–4p excitations, which dominate for higher energies (>30 eV) in the valence region. Full article

(This article belongs to the Section Physics of Materials)

► Show Figures

Figure 1

19 pages, 603 KiB

Open AccessArticle

Chebyshev Polynomials in the Physics of the One-Dimensional Finite-Size Ising Model: An Alternative View and Some New Results

by Nicholay S. Tonchev and Daniel Dantchev

Condens. Matter 2024, 9(4), 53; https://doi.org/10.3390/condmat9040053 - 2 Dec 2024

Abstract

For studying the finite-size behavior of the Ising model under different boundary conditions, we propose an alternative to the standard transfer matrix technique approach based on Abelès theorem and Chebyshev polynomials. Using it, one can easily reproduce the known results for periodic boundary [...] Read more.

For studying the finite-size behavior of the Ising model under different boundary conditions, we propose an alternative to the standard transfer matrix technique approach based on Abelès theorem and Chebyshev polynomials. Using it, one can easily reproduce the known results for periodic boundary conditions concerning the Lee–Yang zeros, the exact position-space renormalization-group transformation, etc., and can extend them by deriving new results for antiperiodic boundary conditions. Note that in the latter case, one has a nontrivial order parameter profile, which we also calculate, where the average value of a given spin depends on the distance from the seam with the opposite bond in the system. It is interesting to note that under both boundary conditions, the one-dimensional case exhibits Schottky anomaly. Full article

(This article belongs to the Section Condensed Matter Theory)

► Show Figures

Figure 1

11 pages, 1091 KiB

Open AccessArticle

The Effect of an Anisotropic Scattering Rate on the Magnetoresistance of a Metal: A Cuprate-Inspired Analysis

by Giovanni Mirarchi and Sergio Caprara

Condens. Matter 2024, 9(4), 52; https://doi.org/10.3390/condmat9040052 - 29 Nov 2024

Abstract

Inspired by the phenomenology of high-critical-temperature superconducting cuprates, we investigate the effect of an anisotropic scattering rate on the magnetoresistance of a metal, relying on Chambers’ solution to the Boltzmann equation. We find that if the scattering rate is enhanced near points of [...] Read more.

Inspired by the phenomenology of high-critical-temperature superconducting cuprates, we investigate the effect of an anisotropic scattering rate on the magnetoresistance of a metal, relying on Chambers’ solution to the Boltzmann equation. We find that if the scattering rate is enhanced near points of the Fermi surface with a locally higher density of states, an extended regime is found where the magnetoresistance varies linearly with the magnetic field. We then apply our results to fit the experimental magnetoresistance of La_1.6−xNd_0.4Sr_xCuO₄ and speculate about the possible source of anisotropic scattering. Full article

(This article belongs to the Special Issue Superstripes Physics, 3rd Edition)

► Show Figures

Figure 1

7 pages, 1325 KiB

Open AccessArticle

The Electron–Phonon Interaction in Non-Stoichiometric Bi₂Sr₂CaCu₂O_8+δ Superconductor Obtained from the Diffuse Elastic Scattering of Helium Atoms

by Giorgio Benedek, Joseph R. Manson, Salvador Miret-Artés, Detlef Schmicker and Jan Peter Toennies

Condens. Matter 2024, 9(4), 51; https://doi.org/10.3390/condmat9040051 - 25 Nov 2024

Abstract

Previously, helium atom scattering (HAS) has been shown to probe the electron–phonon interaction at conducting crystal surfaces via the temperature dependence of the specular peak intensity. This method is now extended to non-stoichiometric superconductors. The electron–phonon interaction, as expressed by the mass-enhancement factor [...] Read more.

Previously, helium atom scattering (HAS) has been shown to probe the electron–phonon interaction at conducting crystal surfaces via the temperature dependence of the specular peak intensity. This method is now extended to non-stoichiometric superconductors. The electron–phonon interaction, as expressed by the mass-enhancement factor λ, is derived from the temperature dependence of the diffuse elastic scattering intensity, which specifically depends on the non-stoichiometric component responsible for superconductivity. The measured value of the mass-enhancement factor for Bi₂Sr₂CaCu₂O_8+δ at the optimal doping δ = 0.16 is λ = 0.55 ± 0.08 is in good agreement with values of λ recently estimated with other methods. This also confirms the relevant role of electron–phonon interaction in high-temperature non-stoichiometric cuprate superconductors. Full article

(This article belongs to the Special Issue Complexity in Quantum Materials: In Honor of Prof. K.A. Muller)

► Show Figures

Figure 1

9 pages, 522 KiB

Open AccessArticle

Renormalization of Fermi Velocity and Band Gap in a Two-Dimensional System near a Conducting Plate at Finite Temperature

by Jeferson Danilo L. Silva, Alessandra N. Braga, Wagner P. Pires, Danilo T. Alves and Van Sérgio Alves

Condens. Matter 2024, 9(4), 50; https://doi.org/10.3390/condmat9040050 - 24 Nov 2024

Abstract

In a recent work, it was demonstrated within the framework of Pseudo Quantum Electro-dynamics (PQED) at zero temperature that the logarithmic renormalization of the Fermi velocity in a graphene sheet is inhibited by the presence of a single parallel conducting plate. In the [...] Read more.

In a recent work, it was demonstrated within the framework of Pseudo Quantum Electro-dynamics (PQED) at zero temperature that the logarithmic renormalization of the Fermi velocity in a graphene sheet is inhibited by the presence of a single parallel conducting plate. In the present study, aiming for a more general and realistic approach, we explore the renormalization of the Fermi velocity and mass (band gap) in a two-dimensional system influenced by a conducting plate at finite temperature, also in the context of PQED. Our findings refine previous results in the literature and provide valuable insights for future investigations on the effects of external conditions within PQED. Full article

(This article belongs to the Special Issue PQED: 30 Years of Reduced Quantum Electrodynamics)

► Show Figures

Figure 1

15 pages, 3122 KiB

Open AccessArticle

Fe₃O₄@SiO₂-NH₂ Functionalized Nanoparticles as a Potential Contrast Agent in Magnetic Resonance

by Brayan Stick Betin Bohorquez, Indry Milena Saavedra Gaona, Carlos Arturo Parra Vargas, Karina Vargas-Sánchez, Jahaziel Amaya, Mónica Losada-Barragán, Javier Rincón and Daniel Llamosa Pérez

Condens. Matter 2024, 9(4), 49; https://doi.org/10.3390/condmat9040049 - 17 Nov 2024

Abstract

The present work proposes a method for the synthesis of a nanoparticle with a superparamagnetic Fe₃O₄ core coated with SiO₂-NH₂ by ultrasound-assisted coprecipitation. Additionally, the nanoparticle is functionalized with a microinflammation biomarker peptide, and its effects on [...] Read more.

The present work proposes a method for the synthesis of a nanoparticle with a superparamagnetic Fe₃O₄ core coated with SiO₂-NH₂ by ultrasound-assisted coprecipitation. Additionally, the nanoparticle is functionalized with a microinflammation biomarker peptide, and its effects on the viability of monkey kidney endothelial cells and the Vero cell line were evaluated. The main physicochemical properties of the nanoparticles were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), a vibrating sample magnetometer (VSM), a field emission scanning electron, Scanning Electron Microscopy (SEM), and High-Resolution Transmission Electron Microscopy (HR-TEM). The results showed that the nanoparticles are spherical, with sizes smaller than 10 nm, with high thermal stability and superparamagnetic properties. They also demonstrated cell viability rates exceeding 85% through Magnetic Resonance Imaging (MRI). The results indicate the potential of these nanoparticles to be used as a contrast agent in magnetic resonance to detect mild brain lesions. Full article

► Show Figures

Figure 1

16 pages, 509 KiB

Open AccessFeature PaperArticle

Single-Defect-Induced Peculiarities in Inverse Faraday-Based Switching of Superconducting Current-Carrying States near a Critical Temperature

by Mihail D. Croitoru and Alexander I. Buzdin

Condens. Matter 2024, 9(4), 48; https://doi.org/10.3390/condmat9040048 - 12 Nov 2024

Abstract

The Inverse Faraday Effect (IFE) is a phenomenon that enables non-thermal magnetization in various types of materials through the interaction with circularly polarized light. This study investigates the impact of single defects on the ability of circularly polarized radiation to switch between distinct [...] Read more.

The Inverse Faraday Effect (IFE) is a phenomenon that enables non-thermal magnetization in various types of materials through the interaction with circularly polarized light. This study investigates the impact of single defects on the ability of circularly polarized radiation to switch between distinct superconducting current states, when the magnetic flux through a superconducting ring equals half the quantum flux,

Φ_{0} / 2

. Using both analytical methods within the standard Ginzburg–Landau theory and numerical simulations based on the stochastic time-dependent Ginzburg–Landau approach, we demonstrate that while circularly polarized light can effectively switch between current-carrying superconducting states, the presence of a single defect significantly affects this switching mechanism. We establish critical temperature conditions above which the switching effect completely disappears, offering insights into the limitations imposed by a single defect on the dynamics of light-induced IFE-based magnetization in superconductors. Full article

(This article belongs to the Special Issue Superstripes Physics, 3rd Edition)

► Show Figures

Figure 1

7 pages, 2589 KiB

Open AccessArticle

Electromagnetic Modeling of Superconducting Bulks in Applied Time-Varying Magnetic Field

by Hocine Menana

Condens. Matter 2024, 9(4), 47; https://doi.org/10.3390/condmat9040047 - 9 Nov 2024

Abstract

An integrodifferential model formulated in terms of the electric vector potential is developed for the 3D numerical modeling of the electromagnetic field in superconducting bulks, for AC losses evaluation. The Newton Raphson method is applied to accelerate the convergence. The model is validated [...] Read more.

An integrodifferential model formulated in terms of the electric vector potential is developed for the 3D numerical modeling of the electromagnetic field in superconducting bulks, for AC losses evaluation. The Newton Raphson method is applied to accelerate the convergence. The model is validated on a benchmark. The comparison results show the accuracy of the model and its performances in terms of computation time compared to classical approaches. Full article

(This article belongs to the Special Issue Selected Papers from the International Conference on Quantum Materials and Technologies (ICQMT2024))

► Show Figures

Figure 1

16 pages, 3203 KiB

Open AccessReview

Readout Methods to Enhance the Performance of Luminescence Thermometers

by Miroslav D. Dramićanin, Abdullah N. Alodhayb and Aleksandar Ćirić

Condens. Matter 2024, 9(4), 46; https://doi.org/10.3390/condmat9040046 - 9 Nov 2024

Abstract

Over the past three decades, luminescence thermometry has gained significant attention among researchers and practitioners. The method has progressed in terms of utilizing temperature-sensitive luminescent materials, obtaining temperature read-outs from luminescence, developing applications, and improving performance. This paper reviews and critically analyzes routes [...] Read more.

Over the past three decades, luminescence thermometry has gained significant attention among researchers and practitioners. The method has progressed in terms of utilizing temperature-sensitive luminescent materials, obtaining temperature read-outs from luminescence, developing applications, and improving performance. This paper reviews and critically analyzes routes for improving luminescence thermometry performance, in particular the sensitivity, accuracy, and precision of the method. These include the use of highly temperature-sensitive probes, temperature read-outs from luminescence with improved sensitivity, multiparameter temperature-reading methods, the applications of principal component analysis and artificial neural networks, and sensor fusion. Full article

(This article belongs to the Section Spectroscopy and Imaging in Condensed Matter)

► Show Figures

Figure 1

Journal Description

Condensed Matter

Latest Articles

Journal Menu

Journal Browser

Highly Accessed Articles

Latest Books

E-Mail Alert

News

Topics

Conferences

Special Issues

Further Information

Guidelines

MDPI Initiatives

Follow MDPI