Spin Gap, Electronic Crossover, and Charge Density Waves in Y-Ba-Cu-O Superconductors*
نویسنده
چکیده
This paper discusses recent NQR/NMR studies performed on Y-Ba-Cu-0 superconductors at the University of Zürich. The work is concerned with normal state properties which are still controversial, for instance the spin-gap effect, i.e. the opening of a pseudo gap in the electron spin excitation spectrum at a temperature 7*, which lies above Tc. We will report on the detection of "anomalies" which are displayed in the temperature dependence of several NMR and NQR quantities measured in the normal state of YBa2Cu408 . These anomalies are interpreted as an electronic crossover which involves a charge redistribution in the C u 0 2 planes and an enhancement of the charge fluctuations. As a possible mechanism of the crossover, a charge density wave instability is proposed.
منابع مشابه
NMR/NQR Spectroscopy
The NMR/NQR group has continued its general research plan of studying current problems of condensed matter physics by employing NMR (nuclear magnetic resonance) and NQR (nuclear quadrupole resonance) methods. These spectroscopies allow one to investigate electronic properties in solids at a microscopic level and thus provide an essential contribution for a better understanding of the materials ...
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