2,146 research outputs found
Fully gapped superconductivity in Ni-pnictide superconductors BaNi2As2 and SrNi2P2
We have performed low-temperature specific heat and thermal conductivity
measurements on the Ni-pnictide superconductors BaNiAs
(=0.7 K and SrNiP (=1.4 K). The temperature
dependences and of the two compounds are similar to the
results of a number of s-wave superconductors. Furthermore, the concave field
responses of the residual for BaNiAs rules out the presence of
nodes on the Fermi surfaces. We postulate that fully gapped superconductivity
could be universal for Ni-pnictide superconductors. Specific heat data on
BaLaNiAs shows a mild suppression of and
relative to BaNiAs.Comment: 5 pages, 3 figures, to be published in J. Phys.: Conf. Se
Measurement of the analyzing power of proton-carbon elastic scattering in the CNI region at RHIC
The single transverse spin asymmetry, A_N, of the p-carbon elastic scattering
process in the Coulomb Nuclear Interference (CNI) region was measured using an
ultra thin carbon target and polarized proton beam in the Relativistic Heavy
Ion Collider (RHIC) at Brookhaven National Laboratory (BNL). In 2004, data were
collected to calibrate the p-carbon process at two RHIC energies (24 GeV, 100
GeV). A_N was obtained as a function of momentum transfer -t. The results were
fit with theoretical models which allow us to assess the contribution from a
hadronic spin flip amplitude.Comment: Contribution to the proceedings of the 16th International Spin
Physics Symposium, spin2004 (Trieste
Low-temperature magneto-thermal transport investigation of a Ni-based superconductor BaNi2As2: Evidence for fully gapped superconductivity
We have performed low-temperature specific heat and thermal conductivity
measurements of the Ni-based superconductor BaNiAs ( =
0.7 K) in magnetic field. In zero field, thermal conductivity shows -linear
behavior in the normal state and exhibits a BCS-like exponential decrease below
. The field dependence of the residual thermal conductivity
extrapolated to zero temperature is indicative of a fully gapped
superconductor. This conclusion is supported by the analysis of the specific
heat data, which are well fit by the BCS temperature dependence from
down to the lowest temperature of 0.1 K.Comment: Physical Review Letters, to be publishe
Novel SOX17 frameshift mutations in endometrial cancer are functionally distinct from recurrent missense mutations.
Effects of the Lattice Discreteness on a Soliton in the Su-Schrieffer-Heeger Model
In this paper we analytically study the effects of the lattice discreteness
on the electron band in the SSH model. We propose a modified version of the TLM
model which is derived from the SSH model using a continuum approximation. When
a soliton is induced in the electron-lattice system, the electron scattering
states both at the bottom of the valence band and the top of the conduction
band are attracted to the soliton. This attractive force induces weakly
localized electronic states at the band edges. Using the modified version of
the TLM model, we have succeeded in obtaining analytical solutions of the
weakly localized states and the extended states near the bottom of the valence
band and the top of the conduction band. This band structure does not modify
the order parameters. Our result coincides well with numerical simulation
works.Comment: to be appear in J.Phys.Soc.Jpn. Figures should be requested to the
author. They will be sent by the conventional airmai
Optical Conductivity and Electronic Structure of CeRu4Sb12 under High Pressure
Optical conductivity [s(w)] of Ce-filled skutterudite CeRu4Sb12 has been
measured at high pressure to 8 GPa and at low temperature, to probe the
pressure evolution of its electronic structures. At ambient pressure, a
mid-infrared peak at 0.1 eV was formed in s(w) at low temperature, and the
spectral weight below 0.1 eV was strongly suppressed, due to a hybridization of
the f electron and conduction electron states. With increasing external
pressure, the mid-infrared peak shifts to higher energy, and the spectral
weight below the peak was further depleted. The obtained spectral data are
analyzed in comparison with band calculation result and other reported physical
properties. It is shown that the electronic structure of CeRu4Sb12 becomes
similar to that of a narrow-gap semiconductor under external pressure.Comment: 8 pages, 9 figure
Resonant neutral particle emission in collisions of electrons with protonated peptides with disulfide bonds at high energies
Magneto-Optical Studies of Exciton Effects in Layer-Type Semiconductors
Both experimental and theoretical works were performed with particular reference to a layer-type semiconductor, GaSe, for a coherent treatment of the exciton-like and the oscillatory Landau-like spectra appearing in a form of their combination in semiconductors in magnetic fields. The interband magneto-absorption and the Faraday rotation were measured in pulsed magnetic fields up to ~200 kOe at low temperatures. The theoretical analysis was based mainly on the exact solution for an extremely anisotropic semiconductor in the magnetic field of arbitrary intensity. The exciton effects are discussed in terms of the energy spectrum, the spectral intensity, and the spectral width by the use of the band parameters deduced from the experimental results
Thermodynamic evidence for field-angle dependent Majorana gap in a Kitaev spin liquid
The exactly-solvable Kitaev model of two-dimensional honeycome magnet leads
to a quantum spin liquid (QSL) characterized by Majorana fermions, relevant for
fault-tolerant topological quantum computations.In the high-field paramagnetic
state of -RuCl, half-integer quantization of thermal Hall
conductivity has been reported as a signature of Majorana fermions, but the
bulk nature of this state remains elusive.Here, from high-resolution heat
capacity measurements under in-plane field rotation, we find strongly
angle-dependent low-energy excitations in the bulk of -RuCl. The
excitation gap has a sextuple node structure, and the gap amplitude increases
with field, exactly as expected for itinerant Majorana fermions in the Kitaev
model.Our thermodynamic results are fully linked with the transport
quantization properties, providing the first demonstration of the bulk-edge
correspondence in a Kitaev QSL.Comment: 8 pages, 7 figure
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