Kinetic-energy driven superconductivity in cuprate superconductors
Kinetic-energy driven superconductivity in cuprate superconductors
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DOI：
10.1142/s0217979215300091
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发表时间：
2015-01
期刊：
影响因子：
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通讯作者：
S. Feng;Y. Lan;Huaisong Zhao;Lulin Kuang;L. Qin;Xixia Ma
中科院分区：
文献类型：
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作者：
S. Feng;Y. Lan;Huaisong Zhao;Lulin Kuang;L. Qin;Xixia Ma
铜酸盐超导体中的超导性发生在电荷载流子掺杂莫特绝缘体上，其中一个核心问题是什么机制导致低于超导（SC）转变温度的电阻损失？在这篇综述中，我们试图总结动能驱动超导机制在铜酸盐超导体超导描述中的基本思想。动能驱动超导的机制是纯电子的，没有声子，其中电荷-载流子配对相互作用直接由通过掺杂浓度的较高功率的自旋激发交换的动能产生。这种动能驱动的 d 波 SC 态由 SC 间隙和准粒子相干性控制，这导致最大 SC 转变温度出现在最佳掺杂附近，然后在欠掺杂和过掺杂状态下降低。特别是，由自旋激发介导的相同电荷-载流子相互作用在粒子-粒子通道中诱导 SC 态，也在粒子-空穴通道中产生正常态赝能隙态。在欠掺杂和最佳掺杂状态下，常态赝能隙交叉温度远大于超导转变温度，然后随着掺杂的增加单调下降，最终与超导穹顶末端的超导性一起消失。这种动能驱动的超导机制还表明，强电子相关性有利于超导性，因为电荷载流子配对机制的主要成分不是来自声子等外部自由度，而是仅来自电子的内部自旋自由度。还回顾了在动能驱动 SC 机制框架内讨论的铜酸盐超导体的典型特性。
Superconductivity in cuprate superconductors occurs upon charge-carrier doping Mott insulators, where a central question is what mechanism causes the loss of electrical resistance below the superconducting (SC) transition temperature? In this review, we attempt to summarize the basic idea of the kinetic-energy driven SC mechanism in the description of superconductivity in cuprate superconductors. The mechanism of the kinetic-energy driven superconductivity is purely electronic without phonons, where the charge-carrier pairing interaction arises directly from the kinetic energy by the exchange of spin excitations in the higher powers of the doping concentration. This kinetic-energy driven d-wave SC-state is controlled by both the SC gap and quasiparticle coherence, which leads to that the maximal SC transition temperature occurs around the optimal doping, and then decreases in both the underdoped and overdoped regimes. In particular, the same charge-carrier interaction mediated by spin excitations that induces the SC-state in the particle-particle channel also generates the normal-state pseudogap state in the particle-hole channel. The normal-state pseudogap crossover temperature is much larger than the SC transition temperature in the underdoped and optimally doped regimes, and then monotonically decreases upon the increase of doping, eventually disappearing together with superconductivity at the end of the SC dome. This kinetic-energy driven SC mechanism also indicates that the strong electron correlation favors superconductivity, since the main ingredient is identified into a charge-carrier pairing mechanism not from the external degree of freedom such as the phonon but rather solely from the internal spin degree of freedom of the electron. The typical properties of cuprate superconductors discussed within the framework of the kinetic-energy driven SC mechanism are also reviewed.