Abstract
Based on measurements of the 63Cu Knight shift and the nuclear spin-lattice relaxation rate under magnetic fields up to 28 T, we find that the pseudogap in the slightly overdoped TlSr2CaCu2O6.88 (Tc=68 K) is due to Cooper pair density fluctuations. Such fluctuations are also found in the underdoped YBa2Cu4O8 (Tc=74 K), but are small and only survive up to Tsf ≃ Tc+15K=90 K, which is much lower than the field-independent pseudogap temperature T* ≃ 160 K. The implication on the phase diagram is discussed. At low temperatures in the superconducting state, a field-induced finite density of states was found in both compounds and is interpreted as due to the quasiparticles outside a vortex core in a d-wave superconductor.
Original language | English |
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Pages (from-to) | 819-822 |
Number of pages | 4 |
Journal | Physica C: Superconductivity and its applications |
Volume | 341-348 |
Issue number | PART 3 |
DOIs | |
Publication status | Published - 2000 |
Externally published | Yes |
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Energy Engineering and Power Technology
- Electrical and Electronic Engineering