1,618 research outputs found
Magnetic properties of PrCu at high pressure
We report a study of the low-temperature high-pressure phase diagram of the
intermetallic compound PrCu, by means of molecular-field calculations and
Cu nuclear-quadrupole-resonance (NQR) measurements under pressure.
The pressure-induced magnetically-ordered phase can be accounted for by
considering the influence of the crystal electric field on the electron
orbitals of the Pr ions and by introducing a pressure-dependent exchange
interaction between the corresponding local magnetic moments. Our experimental
data suggest that the order in the induced antiferromagnetic phase is
incommensurate. The role of magnetic fluctuations both at high and low
pressures is also discussed.Comment: 7 pages, 6 figures, submitted to Eur. Phys. J.
Progress towards Bell-type polarization experiment with thermal neutrons
Experimental tests of Bell-type inequalities distinguishing between quantum
mechanics and local realistic theories remain of considerable interest if
performed on massive particles, for which no conclusive result has yet been
obtained. Only two-particle experiments may specifically test the concept of
spatial nonlocality in quantum theory, whereas single-particle experiments may
generally test the concept of quantum noncontextuality. Here we have performed
the first Bell-type experiment with a beam of thermal-neutron pairs in the
singlet state of spin, as originally suggested by J. S. Bell. These
measurements confirm the quantum-theoretical predictions, in agreement with the
results of the well-known polarization experiments carried out on optical
photons years ago
Optical properties of the charge-density-wave polychalcogenide compounds Te (=Nd, Sm and Gd)
We investigate the rare-earth polychalcogenide Te (=Nd, Sm and
Gd) charge-density-wave (CDW) compounds by optical methods. From the absorption
spectrum we extract the excitation energy of the CDW gap and estimate the
fraction of the Fermi surface which is gapped by the formation of the CDW
condensate. In analogy to previous findings on the related Te (n=2 and
3) families, we establish the progressive closing of the CDW gap and the
moderate enhancement of the metallic component upon chemically compressing the
lattice
Comparison of the TaqMan and LightCycler systems in pharmacogenetic testing: evaluation of the CYP2C9*2/*3 polymorphisms.
Background: Pharmacogenetic testing for drugmetabolizing enzymes is not yet widely used in clinical practice. Methods: In an attempt to facilitate the application of this procedure, we have compared two real-time PCRbased methods, the TaqMan_ and the LightCycler_ for the pharmacogenetic evaluation of CYP2C9*2/*3 polymorphisms. Results and Conclusion: Both procedures are suitable for pharmacogenetic studies. The TaqMan procedure was less expensive in terms of cost per sample, but the TaqMan apparatus is more expensive than the LightCycler apparatus
Further evidence of antibunching of two coherent beams of fermions
We describe an experiment confirming the evidence of the antibunching effect
on a beam of non interacting thermal neutrons. The comparison between the
results recorded with a high energy-resolution source of neutrons and those
recorded with a broad energy-resolution source enables us to clarify the role
played by the beam coherence in the occurrence of the antibunching effect.Comment: 4 pages, 3 figure
Direct experimental evidence of free fermion antibunching
Fermion antibunching was observed on a beam of free noninteracting neutrons.
A monochromatic beam of thermal neutrons was first split by a graphite single
crystal, then fed to two detectors, displaying a reduced coincidence rate. The
result is a fermionic complement to the Hanbury Brown and Twiss effect for
photons.Comment: 4 pages, 2 figure
Optical properties of the Ce and La di-telluride charge density wave compounds
The La and Ce di-tellurides LaTe and CeTe are deep in the
charge-density-wave (CDW) ground state even at 300 K. We have collected their
electrodynamic response over a broad spectral range from the far infrared up to
the ultraviolet. We establish the energy scale of the single particle
excitation across the CDW gap. Moreover, we find that the CDW collective state
gaps a very large portion of the Fermi surface. Similarly to the related rare
earth tri-tellurides, we envisage that interactions and Umklapp processes play
a role in the onset of the CDW broken symmetry ground state
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