1,250 research outputs found
Softening of Magnetic Excitations Leading to Pressure-Induced Quantum Phase Transition in Gapped Spin System KCuCl
KCuCl is a three dimensionally coupled spin dimer system, which undergoes
a pressure-induced quantum phase transition from a gapped ground state to an
antiferromagnetic state at a critical pressure of kbar.
Magnetic excitations in KCuCl at a hydrostatic pressure of 4.7 kbar have
been investigated by conducting neutron inelastic scattering experiments using
a newly designed cylindrical high-pressure clamp cell. A well-defined single
excitation mode is observed. The softening of the excitation mode due to the
applied pressure is clearly observed. From the analysis of the dispersion
relations, it is found that an intradimer interaction decreases under
hydrostatic pressure, while most interdimer interactions increase.Comment: 4 pages, 5 figures, 1 table, jpsj2.cls, to be published in J. Phys.
Soc. Jpn. Vol.76 (2007), the graphic problem of Fig.2 was fixe
"Improvement of the Neutron Energy Spectrometer, COTETRA (Counter Telescope with Thick Radiator)"
Infrared spectroscopy under multi-extreme conditions: Direct observation of pseudo gap formation and collapse in CeSb
Infrared reflectivity measurements of CeSb under multi-extreme conditions
(low temperatures, high pressures and high magnetic fields) were performed. A
pseudo gap structure, which originates from the magnetic band folding effect,
responsible for the large enhancement in the electrical resistivity in the
single-layered antiferromagnetic structure (AF-1 phase) was found at a pressure
of 4 GPa and at temperatures of 35 - 50 K. The optical spectrum of the pseudo
gap changes to that of a metallic structure with increasing magnetic field
strength and increasing temperature. This change is the result of the magnetic
phase transition from the AF-1 phase to other phases as a function of the
magnetic field strength and temperature. This result is the first optical
observation of the formation and collapse of a pseudo gap under multi-extreme
conditions.Comment: 5 pages, 3 figures, accepted for publication in Phys. Rev.
High Speed Detection of Doppler-shifted Hα Lights from Charge Exchange Interaction for Measurement of Fast Ion Distribution
Interaction between Resistive Interchange Mode and Helically Trapped Energetic Ions and its Effects on the Energetic Ions and Bulk Plasmas in LHD
- …