Journal Description
Condensed Matter
Condensed Matter
is an international, peer-reviewed, open access journal on the physics of condensed matter published quarterly online by MDPI.
- Open Access— free for readers, with article processing charges (APC) paid by authors or their institutions.
- High Visibility: indexed within Scopus, ESCI (Web of Science), Inspec, CAPlus / SciFinder, and other databases.
- Rapid Publication: manuscripts are peer-reviewed and a first decision is provided to authors approximately 21 days after submission; acceptance to publication is undertaken in 4.8 days (median values for papers published in this journal in the first half of 2024).
- Recognition of Reviewers: reviewers who provide timely, thorough peer-review reports receive vouchers entitling them to a discount on the APC of their next publication in any MDPI journal, in appreciation of the work done.
Impact Factor:
1.9 (2023);
5-Year Impact Factor:
1.5 (2023)
Latest Articles
Dielectric Response of Yttria–Zirconia Ordered Solids Within Density-Functional Theory in the Random-Phase Approximation
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
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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.
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(This article belongs to the Section Physics of Materials)
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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
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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.
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(This article belongs to the Section Condensed Matter Theory)
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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
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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 La1.6−xNd0.4SrxCuO4 and speculate about the possible source of anisotropic scattering.
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(This article belongs to the Special Issue Superstripes Physics, 3rd Edition)
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The Electron–Phonon Interaction in Non-Stoichiometric Bi2Sr2CaCu2O8+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
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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 Bi2Sr2CaCu2O8+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.
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(This article belongs to the Special Issue Complexity in Quantum Materials: In Honor of Prof. K.A. Muller)
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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
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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.
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(This article belongs to the Special Issue PQED: 30 Years of Reduced Quantum Electrodynamics)
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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
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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
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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.
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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
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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, . 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.
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(This article belongs to the Special Issue Superstripes Physics, 3rd Edition)
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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
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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.
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(This article belongs to the Special Issue Selected Papers from the International Conference on Quantum Materials and Technologies (ICQMT2024))
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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
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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.
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(This article belongs to the Section Spectroscopy and Imaging in Condensed Matter)
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Magnetization Plateaus by the Field-Induced Partitioning of Spin Lattices
by
Myung-Hwan Whangbo, Hyun-Joo Koo, Reinhard K. Kremer and Alexander N. Vasiliev
Condens. Matter 2024, 9(4), 45; https://doi.org/10.3390/condmat9040045 - 4 Nov 2024
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To search for a conceptual picture describing the magnetization plateau phenomenon, we surveyed the crystal structures and the spin lattices of those magnets exhibiting plateaus in their magnetization vs. magnetic field curves by probing the three questions: (a) why only certain magnets exhibit
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To search for a conceptual picture describing the magnetization plateau phenomenon, we surveyed the crystal structures and the spin lattices of those magnets exhibiting plateaus in their magnetization vs. magnetic field curves by probing the three questions: (a) why only certain magnets exhibit magnetization plateaus, (b) why there occur several different types of magnetization plateaus, and (c) what controls the widths of magnetization plateaus. We show that the answers to these questions lie in how the magnets under field absorb Zeeman energy, hence changing their magnetic structures. The magnetic structure of a magnet insulator is commonly described in terms of its spin lattice, which requires the determination of the spin exchanges’ nonnegligible strengths between the magnetic ions. Our work strongly suggests that a magnet under the magnetic field partitions its spin lattice into antiferromagnetic (AFM) or ferrimagnetic fragments by breaking its weak magnetic bonds. Our supposition of the field-induced partitioning of spin lattices into magnetic fragments is supported by the anisotropic magnetization plateaus of Ising magnets and by the highly anisotropic width of the 1/3-magnetization plateau in azurite. The answers to the three questions (a)–(c) emerge naturally by analyzing how these fragments are formed under the magnetic field.
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Open AccessFeature PaperArticle
Simple Model for Tc and Pairing Symmetry Changes in Sr2RuO4 Under (100) Uniaxial Strain
by
Macauley Curtis, Martin Gradhand and James F. Annett
Condens. Matter 2024, 9(4), 44; https://doi.org/10.3390/condmat9040044 - 1 Nov 2024
Abstract
Uniaxial strain in the (100) direction has the effect of increasing the superconducting in Sr2RuO4 from K to over 3 K. The enhanced corresponds to a Lifshitz transition in the Fermi surface topology of this
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Uniaxial strain in the (100) direction has the effect of increasing the superconducting in Sr2RuO4 from K to over 3 K. The enhanced corresponds to a Lifshitz transition in the Fermi surface topology of this unconventional superconductor. We model this using a simple two-dimensional one-band model for the sheet of the Fermi surface. This reproduces the experimental results well if we assume a singlet pairing state. On the other hand, the triplet state does not show any distinct peaks in associated with the Lifshitz transition. A mixed symmetry state pairing of the form can both describe the changes and show a distinct transition temperature for time-reversal symmetry breaking (TRSB).
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(This article belongs to the Special Issue Superstripes Physics, 3rd Edition)
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Kondo Versus Fano in Superconducting Artificial High-Tc Heterostructures
by
Gaetano Campi, Gennady Logvenov, Sergio Caprara, Antonio Valletta and Antonio Bianconi
Condens. Matter 2024, 9(4), 43; https://doi.org/10.3390/condmat9040043 - 31 Oct 2024
Abstract
Recently, the quest for high-Tc superconductors has evolved from the trial-and-error methodology to the growth of nanostructured artificial high-Tc superlattices (AHTSs) with tailor-made superconducting functional properties by quantum design. Here, we report the growth by molecular beam epitaxy (MBE) of a superlattice of
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Recently, the quest for high-Tc superconductors has evolved from the trial-and-error methodology to the growth of nanostructured artificial high-Tc superlattices (AHTSs) with tailor-made superconducting functional properties by quantum design. Here, we report the growth by molecular beam epitaxy (MBE) of a superlattice of Mott insulator metal interfaces (MIMIs) made of nanoscale superconducting layers of quantum confined-space charge in the Mott insulator La2CuO4 (LCO), with thickness L intercalated by normal metal La1.55Sr0.45CuO4 (LSCO) with period d. The critical temperature shows the superconducting dome with Tc as a function of the geometrical parameter L/d showing the maximum at the magic ratio L/d = 2/3 where the Fano–Feshbach resonance enhances the superconducting critical temperature. The normal state transport data of the samples at the top of the superconducting dome exhibit Planckian T-linear resistivity. For L/d > 2/3 and L/d < 2/3, the heterostructures show a resistance following Kondo universal scaling predicted by the numerical renormalization group theory for MIMI nanoscale heterostructures. We show that the Kondo temperature, TK, and the Kondo scattering amplitude, R0K, vanish at L/d = 2/3, while TK and R0K increase at both sides of the superconducting dome, indicating that the T-linear resistance regime competes with the Kondo proximity effect in the normal phase of MIMIs.
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(This article belongs to the Special Issue Superstripes Physics, 3rd Edition)
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Two-Band Electronic Reconstruction Induced via Correlation and CDW Order Effects
by
L. Craco
Condens. Matter 2024, 9(4), 42; https://doi.org/10.3390/condmat9040042 - 30 Oct 2024
Abstract
The emergence of a charge density wave (CDW) in transition-metal dichalcogenides opens up a route to charge order, followed by superconductivity at low temperatures. A key question here concerns how many particle electron–electron interations govern the low-energy electronic structure in the normal and
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The emergence of a charge density wave (CDW) in transition-metal dichalcogenides opens up a route to charge order, followed by superconductivity at low temperatures. A key question here concerns how many particle electron–electron interations govern the low-energy electronic structure in the normal and CDW states. Using dynamical mean-field theory, we explore the many-body properties of an extended, two-band Hubbard model applicable to -TaSe2. We reveal the electronic structure reconstruction in the normal and CDW states driven by two-band dynamical correlations. Our results demonstrate a remarkable renormalization of the Ta- bands crossing the Fermi level, showing a continuous reduction in the CDW gap up to an incomplete gapping, followed by a CDW to a CDW–Mott phase transition pertinent to strongly correlated transition-metal dichalcogenides.
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(This article belongs to the Section Condensed Matter Theory)
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Open AccessFeature PaperReview
Josephson Critical Currents and Related Effects in Ultracold Atomic Superfluid Sytems
by
Verdiana Piselli, Leonardo Pisani and Giancarlo Calvanese Strinati
Condens. Matter 2024, 9(4), 41; https://doi.org/10.3390/condmat9040041 - 30 Oct 2024
Abstract
The Josephson and Proximity effects play a pivotal role in the design of superconducting devices for the implementation of quantum technology, ranging from the standard based to the more exotic twisted high- junctions. Josephson critical currents have been recently
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The Josephson and Proximity effects play a pivotal role in the design of superconducting devices for the implementation of quantum technology, ranging from the standard based to the more exotic twisted high- junctions. Josephson critical currents have been recently investigated also in ultracold atomic systems where a potential barrier acts as a weak link. The unifying feature of the above systems, apart from being superconducting/superfluid, is the presence of spatial inhomogeneity, a feature that has to be properly taken into account in any theoretical approach employed to investigate them. In this work, we review the novel (dubbed LPDA for Local Phase Density Approximation) approach based on a coarse graining of the Bogoliubov–de Gennes (BdG) equations. Non-local and local forms of this coarse graining were utilized when investigating Proximity and Josephson effects. Moreover, the LPDA approach was further developed to include pairing fluctuations at the level of the non-self-consistent t-matrix approximation. The resulting approach, dubbed mLPDA ( LPDA), can be used whenever inhomegeneity and fluctuations effects simultaneously play an important role.
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(This article belongs to the Special Issue Superstripes Physics, 3rd Edition)
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Open AccessArticle
Double-Q Checkerboard Bubble Crystal in Centrosymmetric Tetragonal Magnets
by
Satoru Hayami
Condens. Matter 2024, 9(4), 40; https://doi.org/10.3390/condmat9040040 - 16 Oct 2024
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We report our numerical studies on the emergence of a double-Q checkerboard bubble crystal in centrosymmetric tetragonal magnets. The double-Q checkerboard bubble crystal is characterized by a fourfold-symmetric collinear spin configuration consisting of a superposition of two sinusoidal waves with the
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We report our numerical studies on the emergence of a double-Q checkerboard bubble crystal in centrosymmetric tetragonal magnets. The double-Q checkerboard bubble crystal is characterized by a fourfold-symmetric collinear spin configuration consisting of a superposition of two sinusoidal waves with the out-of-plane spin modulations along the [110] and [ 10] directions. The numerical calculations based on the simulated annealing for an effective spin model with the momentum-resolved easy-axis exchange interactions reveal that the double-Q checkerboard bubble crystal is energetically degenerate with the single-Q collinear state when the ordering wave vector lies on the quarter of the reciprocal lattice vector along the direction. We show that such a degeneracy is lifted by considering the biquadratic interaction. We also find that the double-Q checkerboard bubble crystal turns into another double-Q state characterized by the in-plane spin modulations by increasing an external magnetic field.
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Open AccessCommunication
From Phonons to Domain Walls, the Central Peak and “Critical Slowing Down”
by
Ekhard K. H. Salje and Annette Bussmann-Holder
Condens. Matter 2024, 9(4), 39; https://doi.org/10.3390/condmat9040039 - 1 Oct 2024
Abstract
We investigate perovskite oxides from different perspectives, namely their pseudo-harmonic dynamical properties, their dynamical properties when strong anharmonicity exists, and the intriguing functionalities arising from domain walls. Taking these viewpoints together yields a rather complex picture of this material class, which has not
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We investigate perovskite oxides from different perspectives, namely their pseudo-harmonic dynamical properties, their dynamical properties when strong anharmonicity exists, and the intriguing functionalities arising from domain walls. Taking these viewpoints together yields a rather complex picture of this material class, which has not been found in previous approaches. It opens pathways to novel applications and reveals the rich ground states beyond the fictitious belief in the ‘simplicity of perovskites and such structures’.
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(This article belongs to the Special Issue Complexity in Quantum Materials: In Honor of Prof. K.A. Muller)
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Undamped Higgs Modes in Strongly Interacting Superconductors
by
José Lorenzana and Götz Seibold
Condens. Matter 2024, 9(4), 38; https://doi.org/10.3390/condmat9040038 - 30 Sep 2024
Abstract
In superconductors, gauge symmetry is spontaneously broken. According to Goldstone’s theorem, this breaking of a continuous symmetry establishes the existence of the Bogoliubov phase mode while the gauge-invariant response also includes the amplitude fluctuations of the order parameter. The
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In superconductors, gauge symmetry is spontaneously broken. According to Goldstone’s theorem, this breaking of a continuous symmetry establishes the existence of the Bogoliubov phase mode while the gauge-invariant response also includes the amplitude fluctuations of the order parameter. The latter, which are also termed ‘Higgs’ modes in analogy with the standard model, appear at the energy of the spectral gap , when the superconducting ground state is evaluated within the weak-coupling BCS theory, and, therefore, are damped. Previously, we have shown that, within the time-dependent Gutzwiller approximation (TDGA), Higgs modes appear inside the gap with a finite binding energy relative to the quasiparticle continuum. Here, we show that the binding energy of the Higgs mode becomes exponentially small in the weak-coupling limit converging to the BCS solution. On the other hand, well-defined undamped amplitude modes exist in strongly coupled superconductors when the interaction energy becomes of the order of the bandwidth.
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(This article belongs to the Special Issue Superstripes Physics, 3rd Edition)
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Angularly Selective Enhanced Vortex Screening in Extremely Layered Superconductors with Tilted Columnar Defects
by
Gonzalo Rumi, Vincent Mosser, Marcin Konczykowski and Yanina Fasano
Condens. Matter 2024, 9(4), 37; https://doi.org/10.3390/condmat9040037 - 27 Sep 2024
Abstract
We report on two mechanisms of angularly selective enhanced screening in the solid vortex phase of extremely layered superconductors with tilted columnar defects (CDs). We study Bi2Sr2CaCu2O8+δ samples with different densities of CD tilted 45°
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We report on two mechanisms of angularly selective enhanced screening in the solid vortex phase of extremely layered superconductors with tilted columnar defects (CDs). We study Bi2Sr2CaCu2O8+δ samples with different densities of CD tilted 45° from the c-axis, and conduct local ac Hall magnetometry measurements, probing the sustainable current of the vortex system. We reveal two types of maxima in sustainable current for particular directions, detected as dips in the magnetic transmittivity of the vortex system. First, for a smaller number of vortices than of defects, an enhancement of screening is detected at an angular location ∼45° for H applied close to the direction of CD. For a larger number of vortices than of CD, decreases towards the -plane direction upon warming. Second, a pair of additional dips in transmittivity are detected at angles closer to, and quite symmetric with, the -plane. These two types of angularly selective enhanced screening reveal the effective pinning by tilted CD even for the composite vortex lattices nucleated in tilted fields in Bi2Sr2CaCu2O8+δ.
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(This article belongs to the Section Superconductivity)
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Collision Dynamics of One-Dimensional Bose–Einstein Condensates
by
Aaron Wirthwein, Stephan Haas and Sheng-wey Chiow
Condens. Matter 2024, 9(4), 36; https://doi.org/10.3390/condmat9040036 - 27 Sep 2024
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We study the collision dynamics of two Bose–Einstein condensates, with their dynamical wave functions modeled by a set of coupled, time-dependent Gross–Pitaevskii equations. In an effective one-dimensional system, we identify regimes characterized by the relationship between inter- and intra-atomic interactions and the initial
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We study the collision dynamics of two Bose–Einstein condensates, with their dynamical wave functions modeled by a set of coupled, time-dependent Gross–Pitaevskii equations. In an effective one-dimensional system, we identify regimes characterized by the relationship between inter- and intra-atomic interactions and the initial configuration of the system, akin to the equilibrium phase diagram of two interacting Bose condensates. We consider a dynamical setup in which two wave packets are initially at rest, with a small separation about the center of an anisotropic harmonic trap. Upon release, we observe a rapid approach to dynamical equilibrium in the limits of very large and very small inter-particle repulsion, characterized by periodic transmission or reflection of the condensates as distinguishable units, whereas the intermediate, critical regime is characterized by extended transient dynamics, density fracturing, and dynamical mixing.
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Open AccessArticle
Towards the Construction of an Analog Solver for the Schrödinger and Ginzburg–Landau Equations Based on a Transmission Line
by
Krzysztof Pomorski, Łukasz Pluszyński and Eryk Hałubek
Condens. Matter 2024, 9(4), 35; https://doi.org/10.3390/condmat9040035 - 26 Sep 2024
Abstract
The model presented by Gabriel Kron in 1945 is an example of an analog computer simulating quantum phenomena on a hardware level. It uses passive RLC elements to construct a hardware solver for the problem of quantum particles confined by rectangular or other
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The model presented by Gabriel Kron in 1945 is an example of an analog computer simulating quantum phenomena on a hardware level. It uses passive RLC elements to construct a hardware solver for the problem of quantum particles confined by rectangular or other classes of potential. The analytical and numerical validation of Kron’s second model is conducted for different shapes of particle-confining potentials in the one-dimensional case using an LTspice simulator. Thus, there remains potential for obtaining solutions in two- and three-dimensional cases. Here, a circuit model representing a linearized Ginzburg–Landau equation is given. Kron’s second model is generalized by the introduction of linear and non-linear resistive elements. This transforms the deformed Schrödinger equation into a linear dissipative Schrödinger equation and its non-linear form. The quantum mechanical roton problem is the main result of this work and is formulated by means of classical physical states naturally present in the LC classical circular electrical transmission line. The experimental verification of Kron’s model is confirmed.
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(This article belongs to the Special Issue Selected Papers from the International Conference on Quantum Materials and Technologies (ICQMT2024))
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