3,037 research outputs found

    Stoner gap in the superconducting ferromagnet UGe2

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    We report the temperature (TT) dependence of ferromagnetic Bragg peak intensities and dc magnetization of the superconducting ferromagnet UGe2 under pressure (PP). We have found that the low-TT behavior of the uniform magnetization can be explained by a conventional Stoner model. A functional analysis of the data produces the following results: The ferromagnetic state below a critical pressure can be understood as the perfectly polarized state, in which heavy quasiparticles occupy only majority spin bands. A Stoner gap Δ(P)\Delta(P) decreases monotonically with increasing pressure and increases linearly with magnetic field. We show that the present analysis based on the Stoner model is justified by a consistency check, i.e., comparison of density of states at the Fermi energy deduced from the analysis with observed electronic specific heat coeffieients. We also argue the influence of the ferromagnetism on the superconductivity.Comment: 5 pages, 4 figures. to be published in Phys. Rev.

    Vaginal yeasts in the era of "over the counter" antifungals

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    OBJECTIVE: To establish whether there has been any rise in the prevalence of non-albicans Candida species isolated from vaginal swabs since the introduction of “over the counter” antifungal treatments. METHOD: A retrospective review looking at all positive vaginal yeast isolates collected from women attending one genitourinary medicine clinic during the 6 year period from 1993 to 1998 inclusive. All positive vaginal yeast isolates were included, regardless of whether or not the patients were symptomatic. Isolates from HIV positive women were excluded from the analysis. RESULT: No increase in non-albicans vaginal yeast isolates was shown during the period studied. The proportion of non-albicans yeasts remained constant at approximately 5% of the total yeasts isolated. The most common non-albicans yeast isolated was C glabrata. CONCLUSION: There is no evidence from this study to suggest that the increasing use of “over the counter” antifungal treatment has selected for atypical, possibly inherently azole resistant, strains of vaginal yeasts in HIV seronegative women

    Anomalous phase of MnP at very low field

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    Manganese phosphide MnP has been investigated for decades because of its rich magnetic phase diagram. It is well known that the MnP exhibits the ferromagnetic phase transition at \Tc=292 K and the helical magnetic phase below \TN=47 K at zero field. Recently, a novel magnetic phase transition was observed at T=282T^* = 282 K when the magnetic field is lower than 5 Oe. However, the nature of the new phase has not been illuminated yet. In order to reveal it, we performed the AC and the DC magnetization measurements for a single crystal MnP at very low field. A divergent behavior of the real and the imaginary part of the AC susceptibility and a sharp increase of the DC magnetization was observed at TT^*, indicating the magnetic phase transition at TT^*. Furthermore a peculiar temperature hysteresis was observed: namely, the magnetization depends on whether cooling sample to the temperature lower than \TN or not before the measurements. This hysteresis phenomenon suggests the complicated nature of the new phase and a strong relation between the magnetic state of the new phase and the helical structure.Comment: 4 pages, 2 figure

    Magnetic structure, phase diagram, and a new type of spin-flop transition dominated by higher order interaction in a localized 5f system U3Pd20Si6

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    The magnetic structure of the localized-5f uranium intermetallic compound U3Pd20Si6 has been determined by means of a neutron diffraction experiment. Our data demonstrate that this compound has a collinear coupling of the sublattice ordering of the uranium spins on the 4a and 8c sites. We conclude that higher-order exchange and/or quadrupole interactions are necessary to stabilize this unique collinear structure. We discovered a new type of spin-flop transition against the uniaxial anisotropy induced by this collinear coupling

    No Keplerian Disk >10 AU around the Protostar B335: Magnetic Braking or Young Age?

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    We have conducted ALMA cycle 2 observations in the 1.3 mm continuum and in the C18O (2-1) and SO (5_6-4_5) lines at a resolution of ~0.3" toward the Class 0 protostar B335. The 1.3 mm continuum, C18O, and SO emission all show central compact components with sizes of ~40-180 AU within more extended components. The C18O component shows signs of infalling and rotational motion. By fitting simple kinematic models to the C18O data, the protostellar mass is estimated to be 0.05 Msun. The specific angular momentum, on a 100 AU scale, is ~4.3E-5 km/s*pc. A similar specific angular momentum, ~3E-5 to 5E-5 km/s*pc, is measured on a 10 AU scale from the velocity gradient observed in the central SO component, and there is no clear sign of an infalling motion in the SO emission. By comparing the infalling and rotational motion, our ALMA results suggest that the observed rotational motion has not yet reached Keplerian velocity neither on a 100 AU nor even on a 10 AU scale. Consequently, the radius of the Keplerian disk in B335 (if present) is expected to be 1-3 AU. The expected disk radius in B335 is one to two orders of magnitude smaller than those of observed Keplerian disks around other Class 0 protostars. Based on the observed infalling and rotational motion from 0.1 pc to inner 100 AU scales, there are two possible scenarios to explain the presence of such a small Keplerian disk in B335: magnetic braking and young age. If our finding is the consequence of magnetic braking, ~50% of the angular momentum of the infalling material within a 1000 AU scale might have been removed, and the magnetic field strength on a 1000 AU scale is estimated to be ~200 uG. If it is young age, the infalling radius in B335 is estimated to be ~2700 AU, corresponding to a collapsing time scale of ~5E4 yr.Comment: Accepted by Ap

    Observation of Modulated Quadrupolar Structures in PrPb3

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    Neutron diffraction measurements have been performed on the cubic compound PrPb3 in a [001] magnetic field to examine the quadrupolar ordering. Antiferromagnetic components with q=(1/2+-d 1/2 0), (1/2 1/2+-d 0) (d~1/8) are observed below the transition temperature TQ (0.4 K at H=0) whose amplitudes vary linear with H and vanish at zero field, providing the first evidence for a modulated quadrupolar phase. For H<1 T, a non-square modulated state persists even below 100 mK suggesting quadrupole moments associated with a Gamma3 doublet ground state to be partially quenched by hybridization with conduction electrons.Comment: Physical Review Letters, in press. 4 pages, 4 figure

    Stabilization of a Fabry-Perot interferometer using a suspension-point interferometer

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    A suspension-point interferometer (SPI) is an auxiliary interferometer for active vibration isolation, implemented at the suspension points of the mirrors of an interferometric gravitational wave detector. We constructed a prototype Fabry-Perot interferometer equipped with an SPI and observed vibration isolation in both the spectrum and transfer function. The noise spectrum of the main interferometer was reduced by 40 dB below 1 Hz. Transfer function measurements showed that the SPI also produced good vibration suppression above 1 Hz. These results indicate that SPI can improve both the sensitivity and the stability of the interferometer.Comment: 14 pages, 8 figures; added discussion; to be published in Physics Letters

    The Phonology of Landawe Language

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    This study aims at investigating the phonology of Landawe Language. The data collecting was done by participant speaking and scrutinizing methods. It was analyzed using apportioned methods. Landawe language has 10 vowel sounds, but there are only five sounds proved as vowel phonemes, they are /i, a, e, o, u/. Besides, Landawe language has 18consonant sounds, they are:/b/, /p/, /d/, /t/, /g/, /k/, /ŋ/, /m/, /n/, /s/, /h/, /l/, /r/, /c/ /y/, /j/, /w/, and /ʔ/. Those consonant sounds are proved as the phoneme. Based on the distribution of the consonant, there is not any consonant that places the final position. They just place the initial and the medial of the word, except /ʔ/ and /y/that only place the medial position, and /j/ that only place the initial position. It means that Landawe language is categorized as vocalist language

    Local Moment Formation in the Periodic Anderson Model with Superconducting Correlations

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    We study local moment formation in the presence of superconducting correlations among the f-electrons in the periodic Anderson model. Local moments form if the Coulomb interaction U>U_cr. We find that U_cr is considerably stronger in the presence of superconducting correlations than in the non-superconducting system. Our study is done for various values of the f-level energy and electronic density. The smallest critical U_cr values occur for the case where the number of f- electrons per site is equal to one. In the presence of d-wave superconducting correlations we find that local moment formation presents a quantum phase transition as function of pressure. This quantum phase transition separates a region where local moments and d-wave superconductivity coexist from another region characterized by a superconducting ground state with no local moments. We discuss the possible relevance of these results to experimental studies of the competition between magnetic order and superconductivity in CeCu_2Si_2.Comment: 4 pages. accepted for publication in Phys. Rev.
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