Quantum oscillations and the Fermi surface in an underdoped high-[T.sub.c] superconductor
Article Abstract:
Quantum oscillations are observed in the electrical resistance of the oxygen-ordered copper oxide Y[Ba.sub.2][Cu.sub.3][O.sub.6.5], which has shown the existence of a well-defined Fermi surface in the ground state of underdoped copper oxides, once superconductivity is suppressed by a magnetic field. The high-transition-temperature ([T.sub.c]) superconductors can be interpreted in two ways, where either a small pocket is part of the band structure specific to Y[Ba.sub.2][Cu.sub.3][O.sub.6.5] or small pockets arise from a topological change at a critical point in the phase diagram.
Publication Name: Nature
Subject: Zoology and wildlife conservation
ISSN: 0028-0836
Year: 2007
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Oscillations of cyclic AMP in hormone-stimulated insulin-secreting beta-cells
Article Abstract:
A ratiometric evanescent-wave-microscopy approach is introduced to measure cyclic AMP (cAMP) concentration beneath the plasma membrane, and it is shown that insulin-secreting beta-cells respond to glucagon and GLP-1 with marked cAMP oscillations. It is suggested that brief transient of [cAMP](sub i) are important in the selective regulation of rapid local cytoplasmic events, whereas prolonged [cAMP](sub i) elevation is required for long-term effects involved in regulating cell survival and proliferation.
Publication Name: Nature
Subject: Zoology and wildlife conservation
ISSN: 0028-0836
Year: 2006
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Microwave oscillations of a nanomagnet driven by a spin-polarized current
Article Abstract:
A technique that allows direct electrical measurements of microwave-frequency dynamics in individual nanomagnets, propelled by a d.c. Spin-polarized current is demonstrated. Spin transfer can produce several different types of magnetic excitation.
Publication Name: Nature
Subject: Zoology and wildlife conservation
ISSN: 0028-0836
Year: 2003
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