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UTe2 is a recently discovered spin-triplet superconductor. One of the characteristic features of UTe2 is a magnetic field (H)-boosted superconductivity above 16 T when H is applied exactly parallel to the b axis. To date, this superconducting (SC) state has not been thoroughly investigated, and the SC properties as well as the spin state of this high-H SC (HHSC) phase are not well understood. In this study, we performed AC magnetic susceptibility and nuclear magnetic resonance (NMR) measurements and found that, up to 24.8 T, the HHSC state is intrinsic to UTe2 and quite sensitive to the H angle, and that its SC character is different from that in the low-H SC (LHSC) state. The dominant spin component of the spin-triplet pair is along the a axis in the LHSC state but is changed in the HHSC state along the b axis. Our results indicate that H-induced multiple SC states originate from the remaining spin degrees of freedom., 6 pages, 3 figures, 2 tables

The recently discovered superconductor UTe$_2$, with a T$_c$ between 1.5~K and 2~K, is attracting much attention due to strong suspicion of spin-triplet and topological superconductivity. Its properties under magnetic field are also remarkable, with field-reinforced and field-induced superconducting phases. Here, we report the first complete thermodynamic determination of the phase diagram for fields applied along the three crystallographic directions. Measurements were performed up to 36~T along the hard magnetisation $b$~axis in order to follow the superconducting transition up to the metamagnetic transition at $H_{m} = 34.75$~T. They reveal the existence of a phase transition line within the superconducting phase, and drastic differences occurring between these two phases. Detailed analysis supports a different spin state between the two phases, implying a low-field spin-triplet to high-field spin-singlet transition, a unique case among superconductors, giving insight on the mechanisms leading to spin-triplet superconductivity., Main paper : 17 pages and 15 figures, supplementary material : 17 pages and 17 figures

Multiple unconventional superconducting phases are suspected to be driven by magnetic fluctuations in the heavy-fermion paramagnet UTe$_2$, and a challenge is to identify the signatures of the electronic correlations, including the magnetic fluctuations, in the bulk physical quantities. Here, we investigate thoroughly the anisotropy of the electrical resistivity of UTe$_2$ under intense magnetic fields up to 70~T, for different electrical-current and magnetic-field configurations. Two characteristic temperatures and an anisotropic low-temperature Fermi-liquid-like coefficient $A$, controlled by the electronic correlations, are extracted. Their critical behavior near the metamagnetic transition induced at $\mu_0H_m\simeq35$~T for $\mathbf{H}\parallel\mathbf{b}$ is characterized. Anisotropic scattering processes are evidenced and magnetic fluctuations are proposed to contribute, via a Kondo hybridization, to the electrical resistivity. Our work appeals for a microscopic modeling of the anisotropic contributions to the electrical resistivity as a milestone for understanding magnetically-mediated superconductivity in UTe$_2$., Comment: - Main text: 10 pages, 5 Figures and 60 References - Supplemental Material: 5 pages, 5 Figures, 1 Table and 11 References - there was a problem with Refs. in version 1 of the preprint, this is corrected in version 2 of the preprint

Various materials are developed and applied for drug delivery systems (DDS). Of these, photocatalytic materials are considered one of the attractive materials for DDS. Because titanium dioxide used as a photocatalyst is safe for living organisms and can be prepared the various modifications. Therefore, it is possible to apply some drugs or antibodies for the surface of photocatalytic materials. These materials can be delivered and be concentrated to targeting organs and cells by the combination with magnetic nano particles. Further, it is possible not only to control the drug releasing by photocatalytic reaction but also to kill target cells directly by photocatalytic reaction. In addition to the possibility of photocatalysts as DDS materials, photocatalyst is also the attractive materials as antibacterial/antiviral materials. The infection of SARS-CoV-2 is the serious problem in the world. Then, we introduce the antibacterial/antiviral test method using photocatalytic materials and its application including in water purification, because we expect to apply for antibacterial/antiviral. Thus, this paper introduces the potential of photocatalytic materials as follows;the potential of photocatalytic materials as DDS and cancer treatments, test methods for antibacterial/antiviral effects by photocatalytic reactions, the potential of photocatalytic materials as medical applications, the inactivation of SARS-CoV-2 by photocatalytic reaction, and water purification.

International audience; We report on magnetic-torque and resistivity measurements of the heavy-fermion compound CeCoIn5 in static magnetic fields up to 36 T and temperatures down to 50 mK. While quantum oscillations of the de Haas-van Alphen (dHvA) as well as the Shubnikov-de Haas (SdH) effect confirm the previously reported Fermi surfaces, an analysis of the field dependence reveals two anomalous features. The first is seen at about 22 T as a sharp anomaly in the resistivity for current applied along the a direction. The second appears as nonmonotonic field-dependent oscillation frequencies and amplitudes in both dHvA and SdH signals. This second feature emerges at about 28 T. This field is close to that of the nematic transition reported for CeRhIn5 and the proposed Lifshitz transition in CeIrIn5. We discuss possible common grounds of these latter features that might originate from the very similar band structures of these materials.

The discovery of superconductivity in the heavy-fermion paramagnet UTe$_2$ has attracted a lot of attention, particularly due to the reinforcement of superconductivity near pressure- and magnetic-field-induced magnetic quantum phase transitions. A challenge is now to characterize the effects of combined pressure and magnetic fields applied along variable directions in this strongly anisotropic paramagnet. Here, we present an investigation of the electrical resistivity of UTe$_2$ under pressure up to 3~GPa and pulsed magnetic fields up to 58~T along the hard magnetic crystallographic directions $\mathbf{b}$ and $\mathbf{c}$. We construct three-dimensional phase diagrams and show that, near the critical pressure, a field-enhancement of superconductivity coincides with a boost of the effective mass related to the collapse of metamagnetic and critical fields at the boundaries of the correlated paramagnetic regime and magnetically-ordered phase, respectively. Beyond the critical pressure, field-induced transitions precede the destruction of the magnetically-ordered phase, suggesting an antiferromagnetic nature. By bringing new elements about the interplay between magnetism and superconductivity, our work appeals for microscopic theories describing the anisotropic properties of UTe$_2$ under pressure and magnetic field., 12 pages, 7 figures

It is unexpected that a spin-glass (SG) transition, which generally occurs only in systems with some form of disorder, was observed in the ThCr

The novel spin-triplet superconductor candidate UTe

The novel spin-triplet superconductor candidate UTe2 was discovered only recently at the end of 2018 and attracted enormous attention. We review key experimental and theoretical progress which has been achieved in different laboratories. UTe2 is a heavy-fermion paramagnet, but right after the discovery of superconductivity it has been expected to be close to a ferromagnetic instability showing many similarities to the U-based ferromagnetic superconductors, URhGe and UCoGe. The competition between different types of magnetic interactions and the duality between the local and itinerant character of the 5f Uranium electrons, as well as the shift of the U valence appear as key parameters in the rich phase diagrams discovered recently under extreme conditions like low temperature, high magnetic field, and pressure. We discuss macroscopic and microscopic experiments at low temperature to clarify the normal phase properties at ambient pressure. Special attention will be given to the occurrence of a metamagnetic transition at Hm = 35 T for a magnetic field applied along the hard magnetic axis b. Adding external pressure leads to strong changes in the magnetic and electronic properties with a direct feedback on superconductivity. Attention will be given on the possible evolution of the Fermi surface as a function of magnetic field and pressure. Superconductivity in UTe2 is extremely rich exhibiting various unconventional behaviors which will be highlighted. It shows an exceptionally huge superconducting upper critical field with a re-entrant behavior under magnetic field and the occurrence of multiple superconducting phases in the temperature field, pressure phase diagram. There is evidence for spin-triplet pairing. The different theoretical approaches will be described. Notably we discuss that UTe2 is a possible example for the realization of a fascinating topological superconductor., Comment: 47 pages, 53 figures, submitted to J. Phys.: Condens. Matter as "Topical Review"

A new ternary uranium germanide U

We report a comprehensive de Haas-van Alphen (dHvA) study of the heavy-fermion material CeRhIn_{5} in magnetic fields up to 70 T. Several dHvA frequencies gradually emerge at high fields as a result of magnetic breakdown. Among them is the thermodynamically important β_{1} branch, which has not been observed so far. Comparison of our angle-dependent dHvA spectra with those of the non-4f compound LaRhIn_{5} and with band-structure calculations evidences that the Ce 4f electrons in CeRhIn_{5} remain localized over the whole field range. This rules out any significant Fermi-surface reconstruction, either at the suggested nematic phase transition at B^{*}≈30 T or at the putative quantum critical point at B_{c}≃50 T. Our results rather demonstrate the robustness of the Fermi surface and the localized nature of the 4f electrons inside and outside of the antiferromagnetic phase.

It is unexpected that a spin-glass (SG) transition, which generally occurs only in systems with some form of disorder, was observed in the ThCr2Si2-type compound PrAu2Si2 at a temperature of ∼3 K. This puzzling phenomenon was later explained based on a novel dynamic frustration model that does not involve static disorder. We present the results of re-verification of the reported SG behaviors by measuring the physical properties of three polycrystalline PrAu2Si2 samples annealed under different conditions. Indeed, in the sample annealed at 827 °C for one week, a SG transition does occur at a temperature of T f ∼ 2.8 K as that reported previously in the literature. However, it is newly found that the SG effect is actually more pronounced in the as-cast sample, and almost completely disappears in the well-annealed (at 850 °C for four weeks) sample. The annealing effect observed in PrAu2Si2, that is, SG to paramagnetism transition is discussed by comparing with earlier results reported on the same system and other isomorphic compounds.

The superconducting properties of rhombohedral LaIr

Fabry disease (FD) is a multisystemic disease that has previously been reported to result in poorer quality of life and psychosocial functioning in impacted adults. However, prior to the current study, limited data were available on the impact of FD in children and adolescents. Therefore, the present study examined the differences of quality of life, psychosocial functioning, and depression in children with FD as compared with a healthy sample. Results indicated that children with FD were experiencing poorer quality of life than their healthy counterparts. Notably, results consistently identified adolescents with FD as more heavily impacted than younger children, although not to the same degree as adults with FD as reported in previous studies. Therefore, adolescence may be a critical point in the development of individuals with FD during which effective multidisciplinary interventions could be utilized to prevent poor quality of life and psychosocial functioning in adulthood.

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Background Juvenile dermatomyositis (JDM), a rare autoimmune disease, accounts for more than 80% of idiopathic inflammatory myopathy childhood cases, making it the most common idiopathic inflammatory myopathy among children. The average age of onset is approximately 7 years and commonly leads a chronic course. Symptoms of JDM include cutaneous features (Gottron's rash, heliotrope rash, or nail fold capillary changes), musculoskeletal features, calcinosis and lipodystrophy (a symmetrical deficit of subcutaneous fatty tissue), and acanthosis (thickening of the skin). Despite improvement in treatment regimens and the lowering of mortality rates, some children still lose their lives to JDM. This study assessed the effects of caring for a child diagnosed with JDM on the family system. Methods Participants included 36 mothers and 3 fathers of a child diagnosed with JDM. Parents were administered self-report measures, which assessed the overall family functioning (PedsQL-Family Impact Module), and the parents' mood and level of distress (profile of mood states). Additionally, parents were administered a semi-structured interview that included background information, psychosocial information, and sources of support. Results and conclusion Families of children with JDM reported difficulties in family functioning, communication problems, and an increased number of conflicts. Parents appeared to be experiencing higher than average levels of worry, worse physical functioning, and family relationships when compared to normative populations. Parents would benefit from psychosocial support due to the many challenges associated with caring for a child with JDM.

URu2Si2 is one of the most enigmatic strongly correlated electron systems and offers a fertile testing ground for new concepts in condensed matter science. In spite of >30 years of intense research, no consensus on the order parameter of its low-temperature hidden-order phase exists. A strong magnetic field transforms the hidden order into magnetically ordered phases, whose order parameter has also been defying experimental observation. Here, thanks to neutron diffraction under pulsed magnetic fields up to 40 T, we identify the field-induced phases of URu2Si2 as a spin-density-wave state. The transition to the spin-density wave represents a unique touchstone for understanding the hidden-order phase. An intimate relationship between this magnetic structure, the magnetic fluctuations and the Fermi surface is emphasized, calling for dedicated band-structure calculations., The strongly-correlated electron system URu2Si2 possesses a hidden-order phase whose order parameter remains unidentified. Here, the authors demonstrate the development of spin-density-wave phases in URu2Si2 under high magnetic fields, providing a potential in-road to understanding this system.

In high temperature superconductors, local and excessive temperature rise occurs after normal transition because normal zone propagation velocities are slow at high operation temperature and then the superconductors may be degraded or burned. Therefore, it is essential to detect the temperature rise in high temperature superconducting coils and protect them as soon as possible. The authors have presented a detection method based on time-frequency visualization of AE signals. In this paper, the authors discuss detection and frequency analysis of AE signals accompanying with epoxy cracks caused by thermal expansion in an HTS coil by using the method.

The normal zone propagation velocities in high T c superconductors are slow at high operation temperature and therefore local and excessive temperature rise generates at quench occurrence, and then the superconductors are degraded or burned. Therefore it is essential to detect the temperature rise in high T c superconducting (HTS) coils as soon as possible and protect them. The authors have presented a quench detection method for HTS coils by time–frequency visualization of AE signals and have shown its usefulness for a HTS coil with height and outer diameter of 40–50 mm. In this paper, the authors present a quench detection/protection system based on superior method in quench detection time to the previous method and show its usefulness for a larger HTS coil (height and outer diameter: 160–190 mm) than the previous coil.

We have studied photoluminescence spectra in detail to clarify the character of the isoelectronic traps in dilute GaAsN alloys. Several sharp lines have been observed at the lower energy side of the GaAs bandgap and are in good agreement with the nitrogen pair-related emission lines previously reported. In addition to the nitrogen pair-related lines, some other emission lines have been also observed. Compared with the energies of these emission lines and the nitrogen pair-related emission lines, it was found that the energy differences agree with the longitudinal optical phonon energy at the Γ point of GaAs, showing that the character of isoelectronic traps due to nitrogen pairs in dilute GaAsN alloys is significantly contributed from the conduction band state at the Γ point. The temperature dependence of the peak energy of luminescence due to nitrogen pairs also indicates that the character of isoelectronic traps in dilute GaAsN alloys is due to the conduction band edge state at the Γ point of GaAs. For a dilute GaAsN alloy with lower nitrogen concentration, we have observed that the intensity of an emission line increased superlinearly with excitation power . (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

Our measurements of the ^{59}Co NMR spin-spin relaxation in URh_{0.9}Co_{0.1}Ge reveal a divergence of electronic spin fluctuations in the vicinity of the field-induced quantum critical point at H_{R}≈13 T, around which reentrant superconductivity (RSC) occurs in the ferromagnetic heavy fermion compound URhGe. We map out the strength of spin fluctuations in the (H_{b},H_{c}) plane of magnetic field components and show that critical fluctuations develop in the same limited region near the field H_{R} as that where RSC is observed. This strongly suggests these quantum fluctuations as the pairing glue responsible for the RSC. The fluctuations observed are characteristic of a tricritical point, followed by a phase bifurcation toward quantum critical end points.

We have investigated the excitation power density and nitrogen concentration dependence of the changes in the radiative efficiency of GaAsN alloys to examine the mechanism of the photo-induced improvement of radiative efficiency. With increasing excitation power density, the radiative efficiency increased more rapidly. The measure of the improvement Iafter/Ibefore superlinearly increased with increasing nitrogen concentration x up to ∼1%. This suggests that the nonradiative recombination centers eliminated by photoexcitation are not defects formed by a single nitrogen atom but complexes formed by gathering of several nitrogen atoms. Micro Raman study revealed that the GaAs-like LO mode phonon peak intensity increased with photoexcitation time in a similar way to the increase in the radiative efficiency. Considering that this phenomenon is in a time scale of several seconds, the photo-induced structural changes correspond not to long range inter-diffusion but to local changes in atomic configuration which lead to the decrease in the density of nonradiative recombination centers. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

We performed two-color fluorescence in situ hybridization (FISH) on direct touch smears and liquid-based thin-layer (ThinPrep) cytological preparations of endometrial tumors to detect alterations of chromosome 1 and 17 that present with high incidence in endometrial cancers. The DNA probes used for two-color FISH analysis were a combination of the probes designed for 17cen (cCI 17-321) and 17p13.3 (D17S34), and a combination of the probes designed for 1q12 (D1Z1) and 1p36 (cCI1-5335). Numerical or structural alterations of chromosome 1 and/or 17 were detected in 95% (19 of 20 cases) of the direct touch smears obtained from endometrial cancer, while these alterations were also detected in 93% (12 of 13 cases) of samples obtained from grade 1 endometrioid adenocarcinoma cases, including three cases that could not be diagnosed as positive by conventional Papanicolaou cytopathologic staining. Using ThinPrep cytopathologic preparations, numerical or structural abnormalities were found in 26 (90%) and five (100%) cases, respectively, of samples obtained transcervically from 29 endometrial cancer and five atypical endometrial hyperplasia cases. Therefore, two-color FISH may be a useful diagnostic method for endometrial adenocarcinoma and premalignant lesions that demonstrate only slight cellular atypia in conventional cytopathologic preparations.

We present the magnetic properties and magnetocaloric effect of ternary intermetallic compound Er2PtSi3 with the orthorhombic Ba2LiSi3-type structure. Dc magnetization, ac susceptibilit, magnetic relaxation, electrical resistivity and specific heat measurements indicate that this system undergoes two magnetic phase transitions from a paramagnetic state sequentially to an antifwerromagnetic state at TN=5.4 K and then to a random spin freezing state at Tf=2.4 K. In addition, the large magnetocaloric effect is also observed for the Er2PtSi3 alloy. Near its Neel temperature TN, the maximum magnetic entropy change, relative cooling power and maximum adiabatic temperature change are estimated to be 16.1 Jkg-1K-1, 290 Jkg-1 and 7.7 K, respectively, for a field change of 5 T. These results suggest that Er2PtSi3 should be classified as a re-entrant spin-glass system and can be considered as a potential low-temperature magnetic refrigeration material.

We perform polarized electronic Raman scattering on URu2Si2 single crystals at low temperature down to 8 K in the hidden-order state and under a magnetic field up to 10 T. The hidden-order state is characterized by a sharp excitation at 1.7 meV and a gap in the electronic continuum below 6.8 meV. Both Raman signatures are of pure A2g symmetry. By comparing the behavior of the Raman sharp excitation and the neutron resonance at Q0=(0,0,1), we provide new evidence, constrained by selection rules of the two probes, that the hidden-order state breaks the translational symmetry along the c axis such that Γ and Z points fold on top of each other. The observation of these distinct Raman features with a peculiar A2g symmetry as a signature of the hidden-order phase places strong constraints on current theories of the hidden-order in URu2Si2.

We have studied the temperature dependence of photoluminescence (PL) spectra of GaAsN alloys. The PL peak energy shift due to the temperature change decreases with increasing N concentration of GaAsN alloys. The localized state emission partly contributes to the decrease in the PL peak energy shift. In addition, the small PL peak energy shift at high temperatures is due to the reduction in the temperature dependence of the band gap energy. From the analysis using the Bose-Einstein statistical expression, the average phonon energy is much larger than that expected from the linear interpolation between GaAs and GaN, indicating that the interaction between electrons and phonons localized at N atoms plays an important role in the reduction of the temperature dependence of the band gap energy of GaAsN alloys.

Spectroscopic ellipsometry has been used to investigate the electronic structure near the fundamental absorption edge of GaAsN alloys grown by metalorganic vapor phase epitaxy. The fundamental absorption edge is clearly observed in the imaginary part of the dielectric function and shifts to lower energies with increasing N concentration. In addition, the absorption structure is observed near the E 0 gap energy of GaAs even in GaAsN alloys. This unequivocally shows that the fundamental absorption edge of GaAsN is not shifted from the E 0 gap of GaAs but newly formed by the N incorporation. Thus, the formation of the narrowest band gap of GaAsN alloys is found to be completely different from that of conventional compound semiconductor alloys, such as AlGaAs and GaAsP.

Crack growth of cracked aluminum panels repaired with a bonded composite patch is analyzed to evaluate the effect of repair. An efficient finite element analysis using Mindlin plate elements is developed. The technique is extended to a three-layer model, which consists of patch, adhesive and plate layers. The crack growth behavior of an aluminum panel with the composite patch is discussed on the basis of the Paris relation.

Highly luminescent GaAsN alloy films have been successfully obtained with N concentrations up to 3.1% by metalorganic vapor phase epitaxy (MOVPE). The band-gap bowing parameter estimated from the photoluminescence (PL) peak energy is not constant but dependent on the N concentration; 24.0 eV for N 1% at 20 K, and 22.4 eV for N 1% at room temperature. From the characteristic features of the luminescence properties, the band-edge states are found to be much localized below the conduction band edge, and the emission process at low temperatures is associated with these localized states as in GaPN alloys.

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Using resistivity, heat-capacity, thermal-expansion, and susceptibility measurements we study the normal-state behavior of KFe2As2. We find that both the Sommerfeld coefficient gamma = 103 mJ mol-1 K-2 and the Pauli susceptibility chi = 4x10-4 are strongly enhanced, which confirm the existence of heavy quasiparticles inferred from previous de Haas-van Alphen and ARPES experiments. We discuss this large enhancement using a Gutzwiller slave-boson mean-field calculation, which reveals the proximity of KFe2As2 to an orbital-selective Mott transition. The temperature dependence of the magnetic susceptibility and the thermal expansion provide strong experimental evidence for the existence of a coherence-incoherence crossover, similar to what is found in heavy fermion and ruthenate compounds, due to Hund's coupling between orbitals.