3 research outputs found
Quasiparticle excitation in and around the vortex core of underdoped YBa_2Cu_4O_8 studied by site-selective NMR
We report a site-selective ^{17}O spin-lattice relaxation rate T_1^{-1} in
the vortex state of underdoped YBa_2Cu_4O_8. We found that T_1^{-1} at the
planar sites exhibits an unusual nonmonotonic NMR frequency dependence. In the
region well outside the vortex core, T_1^{-1} cannot be simply explained by the
density of states of the Doppler-shifted quasiparticles in the d-wave
superconductor. Based on T_1^{-1} in the vortex core region, we establish
strong evidence that the local density of states within the vortex core is
strongly reduced.Comment: 5 pages, 3 figure
Microcavity lasing of optically excited cadmium sulfide thin films at room temperature
We report what is believed to be the first observation of lasing of an optically pumped thin CdS film formed by laser ablation on glass. Laser action is observed at room temperature, and the emission peak is at 501 nm. X-ray diffraction shows that the polycrystalline films are of wurtzite structure and have (002) preferred orientation. Fabry–Perot laser modes are spaced 16 nm apart, indicating a cavity length of 2.9 µm. The cavity is formed by consistently self-formed microcavities within the hexagonal lattice