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17 pages, 42688 KiB

Open AccessArticle

The Multi-Detectors System of the PANDORA Facility: Focus on the Full-Field Pin-Hole CCD System for X-ray Imaging and Spectroscopy

by David Mascali, Eugenia Naselli, Sandor Biri, Giorgio Finocchiaro, Alessio Galatà, Giorgio Sebastiano Mauro, Maria Mazzaglia, Bharat Mishra, Santi Passarello, Angelo Pidatella, Richard Rácz, Domenico Santonocito and Giuseppe Torrisi

Condens. Matter 2024, 9(2), 28; https://doi.org/10.3390/condmat9020028 - 20 Jun 2024

Viewed by 338

Abstract

PANDORA (Plasmas for Astrophysics Nuclear Decays Observation and Radiation for Archaeometry) is an INFN project aiming at measuring, for the first time, possible variations in in-plasma

β

-decay lifetimes in isotopes of astrophysical interest as a function of thermodynamical conditions of the in-laboratory [...] Read more.

PANDORA (Plasmas for Astrophysics Nuclear Decays Observation and Radiation for Archaeometry) is an INFN project aiming at measuring, for the first time, possible variations in in-plasma

β

-decay lifetimes in isotopes of astrophysical interest as a function of thermodynamical conditions of the in-laboratory controlled plasma environment. Theoretical predictions indicate that the ionization state can dramatically modify the

β

-decay lifetime (even of several orders of magnitude). The PANDORA experimental approach consists of confining a plasma able to mimic specific stellar-like conditions and measuring the nuclear decay lifetime as a function of plasma parameters. The

β

-decay events will be measured by detecting the

γ

-ray emitted by the daughter nuclei, using an array of 12 HPGe detectors placed around the magnetic trap. In this frame, plasma parameters have to be continuously monitored online. For this purpose, an innovative, non-invasive multi-diagnostic system, including high-resolution time- and space-resolved X-ray analysis, was developed, which will work synergically with the

γ

-rays detection system. In this contribution, we will describe this multi-diagnostics system with a focus on spatially resolved high-resolution X-ray spectroscopy. The latter is performed by a pin-hole X-ray camera setup operating in the 0.5–20 keV energy domain. The achieved spatial and energy resolutions are 450 µm and 230 eV at 8.1 keV, respectively. An analysis algorithm was specifically developed to obtain SPhC (Single Photon-Counted) images and local plasma emission spectrum in High-Dynamic-Range (HDR) mode. Thus, investigations of image regions where the emissivity can change by even orders of magnitude are now possible. Post-processing analysis is also able to remove readout noise, which is often observable and dominant at very low exposure times (ms). Several measurements have already been used in compact magnetic plasma traps, e.g., the ATOMKI ECRIS in Debrecen and the Flexible Plasma Trap at LNS. The main outcomes will be shortly presented. The collected data allowed for a quantitative and absolute evaluation of local emissivity, the elemental analysis, and the local evaluation of plasma density and temperature. This paper also discusses the new plasma emission models, implemented on PIC-ParticleInCell codes, which were developed to obtain powerful 3D maps of the X-rays emitted by the magnetically confined plasma. These data also support the evaluation procedure of spatially resolved plasma parameters from the experimental spectra as well as, in the near future, the development of appropriate algorithms for the tomographic reconstruction of plasma parameters in the X-ray domain. The described setups also include the most recent upgrade, consisting of the use of fast X-ray shutters with special triggering systems that will be routinely implemented to perform both space- and time-resolved spectroscopy during transient, stable, and turbulent plasma regimes (in the ms timescale). Full article

(This article belongs to the Special Issue High Precision X-ray Measurements 2023)

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15 pages, 5612 KiB

Open AccessArticle

Microstructure and Unusual Ferromagnetism of Epitaxial SnO₂ Films Heavily Implanted with Co Ions

by Rustam I. Khaibullin, Amir I. Gumarov, Iskander R. Vakhitov, Andrey A. Sukhanov, Nikolay M. Lyadov, Airat G. Kiiamov, Dilyara M. Kuzina, Valery V. Bazarov and Almaz L. Zinnatullin

Condens. Matter 2024, 9(2), 27; https://doi.org/10.3390/condmat9020027 - 11 Jun 2024

Viewed by 411

Abstract

In this work, we have studied the microstructure and unusual ferromagnetic behavior in epitaxial tin dioxide (SnO₂) films implanted with 40 keV Co⁺ ions to a high fluence of 1.0 × 10¹⁷ ions/cm² at room or elevated substrate temperatures. The aim was to comprehensively understand the interplay between cobalt implant distribution, crystal defects (such as oxygen vacancies), and magnetic properties of Co-implanted SnO₂ films, which have potential applications in spintronics. We have utilized scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), vibrating sample magnetometry (VSM), differential thermomagnetic analysis (DTMA), and ferromagnetic resonance (FMR) to investigate Co-implanted epitaxial SnO₂ films. The comprehensive experimental investigation shows that the Co ion implantation with high cobalt concentration induces significant changes in the microstructure of SnO₂ films, leading to the appearance of ferromagnetism with the Curie temperature significantly above the room temperature. We also established a strong influence of implantation temperature and subsequent high-temperature annealing in air or under vacuum on the magnetic properties of Co-implanted SnO₂ films. In addition, we report a strong chemical effect of ethanol on the FMR spectra. The obtained results are discussed within the model of two magnetic layers, with different concentrations and valence states of the implanted cobalt, and with a high content of oxygen vacancies. Full article

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12 pages, 1360 KiB

Open AccessArticle

Enhancing Spectroscopic Experiment Calibration through Differentiable Programming

by Fabrizio Napolitano

Condens. Matter 2024, 9(2), 26; https://doi.org/10.3390/condmat9020026 - 5 Jun 2024

Viewed by 382

Abstract

In this work, we present an innovative calibration technique leveraging differentiable programming to enhance energy resolution and reduce the energy scale systematic uncertainty in X-ray spectroscopic experiments. This approach is demonstrated using synthetic data and is applicable in general to various spectroscopic measurements. This method extends the scope of differentiable programming for calibration, employing Kernel Density Estimation (KDE) to achieve a target Probability Density Function (PDF) for a fully differentiable model of the calibration. To assess the effectiveness of the calibration, we conduct a toy simulation replicating the entire detector response chain and compare it with a standard calibration. This ensures a robust and reliable calibration methodology, holding promise for improving energy resolution and providing a more versatile and efficient approach without the need for extensive fine-tuning. Full article

(This article belongs to the Special Issue High Precision X-ray Measurements 2023)

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16 pages, 329 KiB

Open AccessArticle

The Effective Potential of Scalar Pseudo-Quantum Electrodynamics in (2 + 1)D

by Leandro O. Nascimento, Carlos A. P. C. Junior and José R. Santos

Condens. Matter 2024, 9(2), 25; https://doi.org/10.3390/condmat9020025 - 30 May 2024

Viewed by 323

Abstract

The description of the electron–electron interactions in two-dimensional materials has a dimensional mismatch, where electrons live in (2 + 1)D while photons propagate in (3 + 1)D. In order to define an action in (2 + 1)D, one may perform a dimensional reduction of quantum electrodynamics in (3 + 1)D (QED4) into pseudo-quantum electrodynamics (PQED). The main difference between this model and QED4 is the presence of a pseudo-differential operator in the Maxwell term. However, besides the Coulomb repulsion, electrons in a material are subjected to several microscopic interactions, which are inherent in a many-body system. These are expected to reduce the range of the Coulomb potential, leading to a short-range interaction. Here, we consider the coupling to a scalar field in PQED for explaining such a mechanism, which resembles the spontaneous symmetry breaking (SSB) in Abelian gauge theories. In order to do so, we consider two cases: (i) by coupling the quantum electrodynamics to a Higgs field in (3 + 1)D and, thereafter, performing the dimensional reduction; and (ii) by coupling a Higgs field to the gauge field in PQED and, subsequently, calculating its effective potential. In case (i), we obtain a model describing electrons interacting through the Yukawa potential and, in case (ii), we show that SSB does not occur at one-loop approximation. The relevance of the model for describing electronic interactions in two-dimensional materials is also addressed. Full article

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

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34 pages, 49917 KiB

Open AccessEditorial

Meeting and Working with K. Alex Müller: Personal Memories

by Annette Bussmann-Holder and Hugo Keller

Condens. Matter 2024, 9(2), 24; https://doi.org/10.3390/condmat9020024 - 8 May 2024

Viewed by 561

Abstract

On 9 January 2023, K [...] Full article

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

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7 pages, 2671 KiB

Open AccessEditorial

Alex’s Vision in Functional Quantum Matter

by Davor Pavuna

Condens. Matter 2024, 9(2), 23; https://doi.org/10.3390/condmat9020023 - 18 Apr 2024

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Abstract

My ‘In Memoriam’ contribution is very personal, as it includes many human and professional insights that I received from Alex Müller himself [...] Full article

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

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12 pages, 4765 KiB

Open AccessFeature PaperArticle

Optimization of a BEGe Detector Setup for Testing Quantum Foundations in the Underground LNGS Laboratory

by Kristian Piscicchia, Alberto Clozza, Diana Laura Sirghi, Massimiliano Bazzi, Nicola Bortolotti, Mario Bragadireanu, Michael Cargnelli, Luca De Paolis, Raffaele Del Grande, Carlo Guaraldo, Mihail Iliescu, Matthias Laubenstein, Simone Manti, Johann Marton, Marco Miliucci, Fabrizio Napolitano, Alessio Porcelli, Alessandro Scordo, Francesco Sgaramella, Florin Sirghi, Sandro Tomassini, Oton Vazquez Doce, Johann Zmeskal and Catalina Curceanu Show full author list Hide full author list

Condens. Matter 2024, 9(2), 22; https://doi.org/10.3390/condmat9020022 - 11 Apr 2024

Viewed by 731

Abstract

In this work, we report on tests performed with an experimental apparatus prototype based on a broad-energy germanium detector aimed at investigating topical, foundational issues in quantum mechanics: i.e., possible violations of the spin-statistics connection and models of dynamical wave function collapse. Our recent phenomenological analyses demonstrated the importance of pushing the research of new physics signal, predicted in these fields, to an energy range below 10 keV. We describe the development of the dedicated data acquisition system and of the pulse shape discrimination algorithm, which have already allowed us to get a factor two improvement in the lower energy threshold. Future plans are discussed to further improve the lower energy threshold to the level of a few keV. Full article

(This article belongs to the Special Issue High Precision X-ray Measurements 2023)

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9 pages, 449 KiB

Open AccessReview

Superconductors without Symmetry Breaking

by Maria Cristina Diamantini

Condens. Matter 2024, 9(2), 21; https://doi.org/10.3390/condmat9020021 - 2 Apr 2024

Viewed by 1026

Abstract

We review the main features of type-III superconductivity. This is a new type of superconductivity that exists in both 2 and 3 spatial dimensions. The main characteristics are emergent granularity and the superconducting gap being opened by a topological mechanism, with no Higgs field involved. Superconductivity is destroyed by the proliferation of vortices and not by the breaking of Cooper pairs, which survive above the critical temperature. The hallmark of this superconductivity mechanism, in 3 spatial dimensions (3D), is the Vogel–Fulcher–Taman scaling of the resistance with temperature. Full article

(This article belongs to the Special Issue Superstripes Physics, 2nd Edition)

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10 pages, 2123 KiB

Open AccessArticle

Topological Phase Diagram of an Interacting Kitaev Chain: Mean Field versus DMRG Study

by Giovanni Nunziante, Alfonso Maiellaro, Claudio Guarcello and Roberta Citro

Condens. Matter 2024, 9(1), 20; https://doi.org/10.3390/condmat9010020 - 20 Mar 2024

Viewed by 1275

Abstract

In this work, we study the topological phase transitions of a Kitaev chain generalized by the addition of nearest-neighbor Coulomb interaction. We show the presence of a robust topological phase as a function of the interaction strength and of the on-site energy with associated non-zero energy Majorana states localized at the chain edges. We provide an effective mean-field model that allows for the self-consistent computation of the mean value of the local particle number operator, and we also perform Density Matrix Renormalization Group numerical simulations based on a tensor network approach. We find that the two methods show a good agreement in reporting the phase transition between trivial and topological superconductivity. Temperature robustness within a physically relevant threshold has also been demonstrated. These findings shed light on an entire class of topological interacting one-dimensional systems in which the effects of residual Coulomb interactions play a relevant role. Full article

(This article belongs to the Section Superconductivity)

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9 pages, 1169 KiB

Open AccessFeature PaperArticle

Enhancing Performances of the VOXES Bragg Spectrometer for XES Investigations

by Simone Manti, Fabrizio Napolitano, Alberto Clozza, Catalina Curceanu, Gabriel Moskal, Kristian Piscicchia, Diana Sirghi and Alessandro Scordo

Condens. Matter 2024, 9(1), 19; https://doi.org/10.3390/condmat9010019 - 7 Mar 2024

Viewed by 1161

Abstract

Utilizing a dispersive crystal for X-ray Emission Spectroscopy (XES) significantly enhances the energy resolution when compared with spectroscopy performed with just silicon drift detectors. This high resolution is particularly valuable for studying metals, as it offers essential insights into their electronic structures and chemical environments. Conducting such experiments in the laboratory, as opposed to synchrotron light sources, presents challenges due to the reduced intensities of X-ray tubes and, consequently, low signal rates, with the effect of increasing the acquisition time. In this study, we demonstrate that XES spectra can be acquired within a few hours for a CuNiZn metallic sample alloy while still maintaining a good energy resolution and a large dynamic range. This is achieved with the VOXES spectrometer, developed at INFN National Laboratories of Frascati (LNF), along with a background reduction procedure that enhances the signal from emission lines under study. This study is a showcase for improving the efficiency of XES in tabletop setup experiments. Full article

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15 pages, 5862 KiB

Open AccessArticle

Experimental Study on Coefficient of Restitution of Small-Sized Spherical Particles during Low-Speed Impact

by Tuo Li, Ran Li, Zhipeng Chi, Yuting Zhang and Hui Yang

Condens. Matter 2024, 9(1), 18; https://doi.org/10.3390/condmat9010018 - 5 Mar 2024

Viewed by 1285

Abstract

This study presents experimental investigations on the normal restitution coefficients of a titanium bead (Ti), zirconia bead (ZrO₂), and amorphous zirconium alloy sphere (Amor). The research explores the influence of particle diameter and collision velocity on the normal restitution coefficient between two independent, identical spherical particles of different materials. The experimental findings demonstrate that increasing the particle diameter results in more effective plastic deformation, leading to higher energy losses and, subsequently, smaller coefficients of restitution. Similarly, higher particle velocities cause more energy dissipation during collisions, resulting in smaller restitution coefficients. Comparing particles of different materials, those with larger yield strengths exhibit more elastic behavior, experience less initial energy loss due to deformation, and reach the maximum restitution coefficient (elastic state) with fewer collisions. This finding suggests that material properties significantly influence the overall energy dissipation and elastic response in the particles. To validate the experimental results, existing models are compared and discussed. Furthermore, potential physical mechanisms responsible for the observed behavior are explored, providing valuable insights into the collision dynamics in spherical particle interactions. Overall, this study contributes to a better understanding of the factors affecting the normal restitution coefficient in particle collisions, enabling the design and optimization of particle systems for diverse applications in condensed matter and related fields. Full article

(This article belongs to the Special Issue Progress in Granular Materials Research in the Asia-Pacific Region)

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15 pages, 5612 KiB

Open AccessArticle

Design and Optimization of Potentially Low-Cost and Efficient MXene/InP Schottky Barrier Solar Cells via Numerical Modeling

by Mohammad Saleh N Alnassar

Condens. Matter 2024, 9(1), 17; https://doi.org/10.3390/condmat9010017 - 3 Mar 2024

Cited by 1 | Viewed by 1277

Abstract

This paper uses numerical modeling to describe the design and comprehensive analysis of cost-effective MXene/n-InP Schottky barrier solar cells. The proposed design utilizes Ti₃C₂T_x thin film, a 2D solution-processible MXene material, as a Schottky transparent conductive electrode (TCE). The simulation results suggest that these devices can achieve power conversion efficiencies (PCEs) exceeding 20% in metal–semiconductor (MS) and metal–interlayer–semiconductor (MIS) structures. Combining the proposed structures with low-cost InP growth methods can reduce the gap between InP and other terrestrial market technologies. This is useful for specific applications that require lightweight and radiation-hard solar photovoltaics. Full article

(This article belongs to the Topic Applications of Photonics, Laser, Plasma and Radiation Physics)

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11 pages, 2811 KiB

Open AccessArticle

Characterization of the SIDDHARTA-2 Setup via the Kaonic Helium Measurement

by Francesco Sgaramella, Francesco Clozza, Leonardo Abbene, Francesco Artibani, Massimiliano Bazzi, Giacomo Borghi, Mario Bragadireanu, Antonino Buttacavoli, Michael Cargnelli, Marco Carminati, Alberto Clozza, Griseld Deda, Raffaele Del Grande, Luca De Paolis, Kamil Dulski, Carlo Fiorini, Carlo Guaraldo, Mihail Iliescu, Masahiko Iwasaki, Aleksander Khreptak, Simone Manti, Johann Marton, Marco Miliucci, Paweł Moskal, Fabrizio Napolitano, Szymon Niedźwiecki, Hiroaki Ohnishi, Kristian Piscicchia, Fabio Principato, Alessandro Scordo, Michal Silarski, Diana Sirghi, Florin Sirghi, Magdalena Skurzok, Antonio Spallone, Kairo Toho, Marlene Tüchler, Johann Zmeskal and Catalina Curceanu Show full author list Hide full author list

Condens. Matter 2024, 9(1), 16; https://doi.org/10.3390/condmat9010016 - 28 Feb 2024

Viewed by 1823

Abstract

The aim of the SIDDHARTA-2 experiment is to perform the first measurement ever of the width and shift induced by the strong interaction to the

2 p \to 1 s

energy transition of kaonic deuterium. This ambitious goal implies a challenging task due [...] Read more.

The aim of the SIDDHARTA-2 experiment is to perform the first measurement ever of the width and shift induced by the strong interaction to the

2 p \to 1 s

energy transition of kaonic deuterium. This ambitious goal implies a challenging task due to the very low X-ray yield of kaonic deuterium, which is why an accurate and thorough characterization of the experimental apparatus is mandatory before starting the data-taking campaign. Helium-4 is an excellent candidate for this characterization since it exhibits a high yield in particular for the

3 d \to 2 p

transition, roughly 100 times greater than that of the kaonic deuterium. The ultimate goal of the work reported in this paper is to study the performances of the full experimental setup in view of the kaonic deuterium measurement. This is carried out by measuring the values of the shift and the width for the

3 d \to 2 p

energy transition of kaonic helium-4, induced by the strong interaction. The values obtained for these quantities, for a total integrated luminosity of ∼31/

p

b

, are

ε_{2 p} = 2.0 \pm 1.2 (stat) \pm 1.5 (syst) eV

and

Γ_{2 p} = 1.9 \pm 5.7 (stat) \pm 0.7 (syst) eV

. The results, compared to the value of the shift measured by the SIDDHARTA experiment

ε_{2 p} = 0 \pm 6 (stat) \pm 2 (syst) eV

, show a net enhancement of the resolution of the apparatus, providing strong evidence of the potential to perform the challenging measurement of the kaonic deuterium. Full article

(This article belongs to the Special Issue High Precision X-ray Measurements 2023)

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10 pages, 2716 KiB

Open AccessArticle

Universal Short-Time Conductance Behavior Emerges between Two Adjacent Reservoirs

by Er’el Granot

Condens. Matter 2024, 9(1), 15; https://doi.org/10.3390/condmat9010015 - 26 Feb 2024

Viewed by 1165

Abstract

When a shutter, which differentiates between two adjacent particles’ reservoirs with a voltage gap, is lifted, a current emerges. In this paper, the temporal dynamics of this emerging current is analyzed. The main results are as follows: (A) the current’s prefactor in the short-time behavior is related to the long-time frequencies, by which the current converges to its equilibrium value (the conductance quantum unit 2e²/h). (B) In the short-time regime, the current is proportional to the square root of the time. (C) The maximum overshoot conductance is bounded by G_max = ζe²/h, where ζ is a universal value which is very close to Euler’s number. (D) Most of these results are valid for a thin wire in 3D, even in the presence of electron–electron interactions. Full article

(This article belongs to the Special Issue New Advances in Condensed Matter Physics)

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13 pages, 674 KiB

Open AccessFeature PaperArticle

The Shrinking Fermi Liquid Scenario for Strange-Metal Behavior from Overdamped Optical Phonons

by Giovanni Mirarchi, Marco Grilli, Götz Seibold and Sergio Caprara

Condens. Matter 2024, 9(1), 14; https://doi.org/10.3390/condmat9010014 - 6 Feb 2024

Viewed by 1167

Abstract

We discuss how the interaction of electrons with an overdamped optical phonon can give rise to a strange-metal behavior over extended temperature and frequency ranges. Although the mode has a finite frequency, an increasing damping shifts spectral weight to progressively lower energies so that despite the ultimate Fermi liquid character of the system at the lowest temperatures and frequencies, the transport and optical properties of the electron system mimic a marginal Fermi liquid behavior. Within this shrinking Fermi liquid scenario, we extensively investigate the electron self-energy in all frequency and temperature ranges, emphasizing similarities and differences with respect to the marginal Fermi liquid scenario. Full article

(This article belongs to the Special Issue Superstripes Physics, 2nd Edition)

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