1,286 research outputs found
Microscopic description of large-amplitude shape-mixing dynamics with local QRPA inertial functions
We introduce a microscopic approach to derive all the inertial functions in
the five-dimensional quadrupole collective Hamiltonian. Local normal modes are
evaluated on the constrained mean field in the quasiparticle random-phase
approximation in order to derive the inertial functions. The collective
Hamiltonians for neutron-rich Mg isotopes are determined with use of this
approach, and the shape coexistence/mixing around the N = 20 region is
analyzed.Comment: 6 pages, 2 figures, Talk given at International Symposium New Faces
of Atomic Nuclei, Okinawa, Japan, Nov. 15-17, 201
General Rule and Materials Design of Negative Effective U System for High-T_c Superconductivity
Based on the microscopic mechanisms of (1) charge-excitation-induced negative
effective U in s^1 or d^9 electronic configurations, and (2)
exchange-correlation-induced negative effective U in d^4 or d^6 electronic
configurations, we propose a general rule and materials design of negative
effective U system in itinerant (ionic and metallic) system for the realization
of high-T_c superconductors. We design a T_c-enhancing layer (or clusters) of
charge-excitation-induced negative effective connecting the superconducting
layers for the realistic systems.Comment: 11 pages, 1 figures, 2 tables, APEX in printin
Magnetization Plateaus in the Spin-1/2 Kagome Antiferromagnets: Volborthite and Vesignieite
The magnetization of two spin-1/2 kagome antiferromagnets, volborthite and
vesignieite, has been measured in pulsed magnetic fields up to 68 T. A
magnetization plateau is observed for each compound near the highest magnetic
field. Magnetizations at saturation are approximately equal to 0.40Ms for both
compounds, where Ms is the fully saturated magnetization, irrespective of a
difference in the distortion of the kagome lattice between the two compounds.
It should be noted that these values of magnetizations are significantly larger
than Ms/3 predicted theoretically for the one-third magnetization plateau in
the spin-1/2 kagome antiferromagnet. The excess magnetization over Ms/3 is
nearly equal to the sum of the magnetizations gained at the second and third
magnetization steps in volborthite, suggesting that there is a common origin
for the excess magnetization and the magnetization steps.Comment: 4 pages, 4 figures. Phys. Rev. B, accepte
- …