5,173 research outputs found
Quantum critical point and superconducting dome in the pressure phase diagram of o-TaS3
We measure the electrical resistance of o-TaS3 between 1K and 300K under
pressures up to 20GPa. We observe a gradual decrease of the charge density wave
transition temperature with increasing pressure P following a mean-field
quantum fluctuation power law with a quantum critical point at a pressure Pc =
11.5GPa. Around the quantum critical point we observe a superconducting dome
with a maximum superconducting transition temperature Tc = 3.1K. Such dome is
similar to superconducting domes around other types of order suggesting that
the QCP is directly responsible for the enhancement of superconductivity
through a universal mechanism still not well understood.Comment: To be published in PRB as a Rapid Communication. 11 pages with 4
figure
Some results on the eigenfunctions of the quantum trigonometric Calogero-Sutherland model related to the Lie algebra E6
The quantum trigonometric Calogero-Sutherland models related to Lie algebras
admit a parametrization in which the dynamical variables are the characters of
the fundamental representations of the algebra. We develop here this approach
for the case of the exceptional Lie algebra E6.Comment: 17 pages, no figure
High pressure effects in fluorinated HgBa2Ca2Cu3O(8+d)
We have measured the pressure sensitivity of Tc in fluorinated
HgBa2Ca2Cu3O(8+d) (Hg-1223) ceramic samples with different F contents, applying
pressures up to 30 GPa. We obtained that Tc increases with increasing pressure,
reaching different maximum values, depending on the F doping level, and
decreases for a further increase of pressure. A new high Tc record (166 K +/- 1
K) was achieved by applying pressure (23 GPa) in a fluorinated Hg-1223 sample
near the optimum doping level. Our results show that all our samples are at the
optimal doping, and that fluorine incorporation decreases the crystallographic
-parameter concomitantly increasing the maximum attainable Tc. This effect
reveals that the compression of the axes is one of the keys that controls
the Tc of high temperature superconductors.Comment: 4 pages, 4 figures, submitted to Phys. Rev.
Optical spin transfer in ferromagnetic semiconductors
Circularly polarized laser pulses that excite electron-hole pairs across the
band gap of (III,Mn)V ferromagnetic semiconductors can be used to manipulate
and to study collective magnetization dynamics. The initial spin orientation of
a photocarrier in a (III,V) semiconductors is determined by the polarization
state of the laser. We show that the photocarrier spin can be irreversibly
transferred to the collective magnetization, whose dynamics can consequently be
flexibly controlled by suitably chosen laser pulses. As illustrations we
demonstrate the feasibility of all optical ferromagnetic resonance and optical
magnetization reorientation.Comment: 8 pages, 3 figure
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