Competition of Superconductivity and Charge Density Waves in Cuprates: Recent Evidence and Interpretation
Explicit and implicit experimental evidence for charge density wave (CDW) presence in high-Tc superconducting oxides is analyzed. The theory of CDW superconductors is presented. It is shown that the observed pseudogaps and dip-hump structures in tunnel and photoemission spectra are manifestations of...
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| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Wiley
2010-01-01
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| Series: | Advances in Condensed Matter Physics |
| Online Access: | http://dx.doi.org/10.1155/2010/681070 |
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| Summary: | Explicit and implicit experimental evidence for charge density wave (CDW) presence in high-Tc superconducting oxides is analyzed. The theory of CDW superconductors is presented. It is shown
that the observed pseudogaps and dip-hump structures in tunnel and photoemission spectra are
manifestations of the same CDW gapping of the quasiparticle density of states. Huge pseudogaps
are transformed into modest dip-hump structures at low temperatures, T, when the electron spectrum superconducting gapping dominates. Heat capacity jumps at the superconducting critical temperature and the paramagnetic limit are calculated for CDW superconductors. For a certain
range of parameters, the CDW state in a d-wave superconductor becomes reentrant with T, the main control quantity being a portion of dielectrcally gapped Fermi surface. It is shown that in
the weak-coupling approximation, the ratio between the superconducting gap at zero temperature
Δ(T=0) and Tc has the Bardeen-Cooper-Schrieffer value for s-wave Cooper pairing and exceeds
the corresponding value for d-wave pairing of CDW superconductors. Thus, large experimentally
found values 2Δ(T=0)/Tc≈5÷8 are easily reproduced with reasonable input parameter values of
the model. The conclusion is made that CDWs play a significant role in cuprate superconductivity. |
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| ISSN: | 1687-8108 1687-8124 |