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arXiv 0801.3577cond-mat.supr-concond-mat.str-el
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赝能隙金属的强关联超导电性

Strongly Correlated Superconductivity rising from a Pseudo-gap Metal

Marco Schiro', Massimo Capone, Michele Fabrizio, Claudio Castellani

摘要:

我们解决了动态平均场论的玩具模型,它具有一个相图惊人的相似,高$T_c$超导体:一个钟形的超导区域附近的莫特绝缘体和正常的相位,从传统的费米液体的赝能隙半金属的莫特过渡的做法。在动力学平均场论中自洽求解的杂质模型的物理基础上,我们引入了一种分析方法来模拟各个相的动力学行为,它非常精确地拟合了数值数据。该方法假设在Mott跃迁附近的赝能隙相中存在严重的波函数重正化,而在Cooper对通道中的顶点修正可以完全抵消这种重正化,结果表明即使在赝能隙正常态中不存在低能准粒子,也可以发展成超导态.出现的整体物理场景,虽然在一个特定的模型和无限协调贝特晶格中解开,可以解释为如此普遍的论点,表明它可以在其他相关系统中实现。

英文摘要:

We solve by Dynamical Mean Field Theory a toy-model which has a phase diagram strikingly similar to that of high $T_c$ superconductors: a bell-shaped superconducting region adjacent the Mott insulator and a normal phase that evolves from a conventional Fermi liquid to a pseudogapped semi-metal as the Mott transition is approached. Guided by the physics of the impurity model that is self-consistently solved within Dynamical Mean Field Theory, we introduce an analytical ansatz to model the dynamical behavior across the various phases which fits very accurately the numerical data. The ansatz is based on the assumption that the wave-function renormalization, that is very severe especially in the pseudogap phase close to the Mott transition, is perfectly canceled by the vertex corrections in the Cooper pairing channel.A remarkable outcome is that a superconducting state can develop even from a pseudogapped normal state, in which there are no low-energy quasiparticles. The overall physical scenario that emerges, although unraveled in a specific model and in an infinite-coordination Bethe lattice, can be interpreted in terms of so general arguments to suggest that it can be realized in other correlated systems.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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