Correlation bag and high-Tc superconductivity.
Correlation bag and high-Tc superconductivity.
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相关袋和高温超导。
DOI：
--
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发表时间：
1990
期刊：
影响因子：
--
通讯作者：
Zhou
中科院分区：
文献类型：
--
作者：
Goodenough;Zhou
From an analysis of the normal-state properties of the high-{Tc} copper oxide superconductors the following features can be established on the basis of single-particle theories: (1) a bandwidth {ital W}{approx}{ital U}{gt}{ital E}{sub {ital p}}, where {ital U} is the on-site correlation energy and {ital E}{sub {ital p}} is the pair binding energy; (2) a {ital W}{approx}8{h bar}{omega}{sub {ital R}} at the narrow-band limit for small-polaron versus itinerant-electron conduction in a mixed-valent system; (3) a {ital W}{approx}{var epsilon}{sub {sigma}}{lambda}{sub {sigma}}{sup 2}, where the covalent mixing parameter {lambda}{sub {sigma}} varies sensitively with the hole concentration and consequently with any local charge fluctuations in a mixed-valent system; (4) on-site and near-neighbor correlation energies that vary sensitively with the bandwidth in the region {ital W}{approx}{ital U}. From the superconductor properties, a {xi}{approx}10 A signals an energy range of perturbed states {h bar}{omega}{approx lt}{ital W}, and superconductive pairs constrained to a small volume in real space which makes necessary the introduction of a nonretarded potential. These features lead us to consider charge fluctuations, induced by strong electron-lattice interactions, where {ital U}{approx gt}{ital W}{approx}8{h bar}{omega}{sub {ital R}}, in which bags'' rich in charge carriers coexist with regions poor in charge carriers together with an important modulationmore » of the bandwidth--and hence the correlation energies--on moving from outside to inside a bag. The problems with the Alexandrov model that have been raised by De Jongh are resolved by the modulation of the correlation energies which adds a new term to the Hamiltonian that gives an additional component to the binding energy. A bag model allows use of the spin-bag formalism but with a renormalization of the charge channel rather than the spin channel to obtain a possible so« less
From an analysis of the normal-state properties of the high-{Tc} copper oxide superconductors the following features can be established on the basis of single-particle theories: (1) a bandwidth {ital W}{approx}{ital U}{gt}{ital E}{sub {ital p}}, where {ital U} is the on-site correlation energy and {ital E}{sub {ital p}} is the pair binding energy; (2) a {ital W}{approx}8{h bar}{omega}{sub {ital R}} at the narrow-band limit for small-polaron versus itinerant-electron conduction in a mixed-valent system; (3) a {ital W}{approx}{var epsilon}{sub {sigma}}{lambda}{sub {sigma}}{sup 2}, where the covalent mixing parameter {lambda}{sub {sigma}} varies sensitively with the hole concentration and consequently with any local charge fluctuations in a mixed-valent system; (4) on-site and near-neighbor correlation energies that vary sensitively with the bandwidth in the region {ital W}{approx}{ital U}. From the superconductor properties, a {xi}{approx}10 A signals an energy range of perturbed states {h bar}{omega}{approx lt}{ital W}, and superconductive pairs constrained to a small volume in real space which makes necessary the introduction of a nonretarded potential. These features lead us to consider charge fluctuations, induced by strong electron-lattice interactions, where {ital U}{approx gt}{ital W}{approx}8{h bar}{omega}{sub {ital R}}, in which bags'' rich in charge carriers coexist with regions poor in charge carriers together with an important modulationmore » of the bandwidth--and hence the correlation energies--on moving from outside to inside a bag. The problems with the Alexandrov model that have been raised by De Jongh are resolved by the modulation of the correlation energies which adds a new term to the Hamiltonian that gives an additional component to the binding energy. A bag model allows use of the spin-bag formalism but with a renormalization of the charge channel rather than the spin channel to obtain a possible so« less