Crossover between magnetism and superconductivity in low H-doped LaFeAsO

By a systematic study of the hydrogen-doped LaFeAsO system by means of dc resistivity, dc magnetometry, and muon-spin spectroscopy we addressed the question of universality of the phase diagram of rare-earth-1111 pnictides. In many respects, the behaviour of LaFeAsO_(1-x)H_(x) resembles that of its widely studied F-doped counterpart, with H^- realizing a similar (or better) electron-doping in the LaO planes. In a x = 0.01 sample we found a long-range SDW order with T_n = 119 K, while at x = 0.05 the SDW establishes only at 38 K and, below T_c = 10 K, it coexists at a nanoscopic scale with bulk superconductivity. Unlike the abrupt M-SC transition found in the parent La-1111 compound, the presence a crossover region makes the H-doped system qualitatively similar to other Sm-, Ce-, or Nd-1111 families.Comment: to appear in Journal of Physics: Condensed Matte

THE REASON WHY PROSTATIC HYPERPLASIA CAUSES LOWER URINARY TRACT SYMPTOMS*

Abstract: In benign prostatic hyperplasia (BPH), the lower urinary tract changes both functionally and organically in association with the enlargement of prostate. Thereby, lower urinary tract symptoms (LUTS) are manifested. LUTS are classified into symptoms in the storage phase and in the voiding phase. The former includes urinary frequency, nocturia, urinary urgency, and incontinence. These are caused by detrusor enlargement and increased bladder sensation which occur in association with urethral resistance increased by urethral compression resulting from BPH. The symptoms caused by difficult voiding due to urethral compression by enlarged prostate are called voiding symptoms, which include urinary hesitation, prolongation of micturition time, weakening of stream, and so on. Aging, cerebral disease, vertebral disease, spinal disease, and heart disease present lower urinary tract symptoms very similar to those associated with BPH and these diseases complicate symptoms of BPH

Exciton States in a Two-dimensional Systems of GaAs/AlAs Multi-quantum Wells under High Magnetic Fields(Research in High Magnetic Fields)

Magneto-optical spectra of a GaAs/AlAs multi-quantum-well sample have been measured in the Faraday configuration at high magnetic fields up to 25 T . These spectra reveal clear excitonic effects on top of the Landau-level structure. The excitonic states are well explained by effective mass calculations that take into account residual electric fields in the sample and the valence band mixing in magnetic fields . The results indicate that Coulomb interaction plays an important role even under very high magnetic fields, in contrast to the common belief that it should be only a weak perturbation to the Landau level. A crossing of the lowest heavy hole free exciton and the lowest light hole free exciton is observed at a magnetic field of about 15 T with σ+polarization, thus achieving a symmetry change in the exciton ground state. The absence of an anticrossing between the light and heavy hole exciton ground state indicate the unimportance of exchange effects

The new MRTOF mass spectrograph following the ZeroDegree spectrometer at RIKEN's RIBF facility

A newly assembled multi-reflection time-of-flight mass spectrograph (MRTOF-MS) at RIKEN's RIBF facility became operational for the first time in spring 2020; further modifications and performance tests using stable ions were completed in early 2021. By using a pulsed-drift-tube technique to modify the ions' kinetic energy in a wide range, we directly characterize the dispersion function of the system for use in a new procedure for optimizing the voltages applied to the electrostatic mirrors. Thus far, a mass resolving power of $R_m > 1\,000\,000$ is reached within a total time-of-flight of only $12.5\,\mathrm{ms}$, making the spectrometer capable of studying short-lived nuclei possessing low-lying isomers. Detailed information about the setup and measurement procedure is reported, and an alternative in-MRTOF ion selection scheme to remove molecular contaminants in the absence of a dedicated deflection device is introduced. The setup underwent an initial on-line commissioning at the BigRIPS facility at the end of 2020, where more than 70 nuclear masses have been measured. A summary of the commissioning experiments and results from a test of mass accuracy will be presented.Comment: 13 pages, 11 figure

A new study of the N=32N=32 and N=34N=34 shell gap for Ti and V by the first high-precision MRTOF mass measurements at BigRIPS-SLOWRI

The atomic masses of $^{55}$Sc, $^{56,58}$Ti, and $^{56-59}$V have been determined using the high-precision multi-reflection time-of-flight technique. The radioisotopes have been produced at RIKEN's RIBF facility and delivered to the novel designed gas cell and multi-reflection system (ZD MRTOF), which has been recently commissioned downstream of the ZeroDegree spectrometer following the BigRIPS separator. For $^{56,58}$Ti and $^{56-59}$V the mass uncertainties have been reduced down to the order of $10\,\mathrm{keV}$, shedding new light on the $N=34$ shell effect in Ti and V isotopes by the first high-precision mass measurements of the critical species $^{58}$Ti and $^{59}$V. With the new precision achieved, we reveal the non-existence of the $N=34$ empirical two-neutron shell gaps for Ti and V, and the enhanced energy gap above the occupied $\nu p_{3/2}$ orbit is identified as a feature unique to Ca. We perform new Monte Carlo shell model calculations including the $\nu d_{5/2}$ and $\nu g_{9/2}$ orbits and compare the results with conventional shell model calculations, which exclude the $\nu g_{9/2}$ and the $\nu d_{5/2}$ orbits. The comparison indicates that the shell gap reduction in Ti is related to a partial occupation of the higher orbitals for the outer two valence neutrons at $N=34$