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arXiv 2210.04046cond-mat.supr-concond-mat.str-el
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铜氧化物超导体中的电荷序与演生对称性

Charge order and emergent symmetries in cuprate superconductors

C. Pépin, H. Freire

AI总结:

本研究用场论中的演生 SU(2) 对称性与 U(1) 规范场解释铜氧化物超导体的电荷序、赝能隙及相关谱学和输运现象。

摘要:

本文介绍了我们近年来对铜氧化物超导体相图所开展的研究。我们阐述了若干场论概念如何能够解释这些化合物令人困惑的性质。文章首先简要介绍近期的实验进展,随后引入演生 SU(2) 对称性的概念,该对称性可在超导序参量与电荷序参量之间进行旋转。我们描述了一个可解模型,在该模型中这一对称性被证明是严格的,并以非线性 σ 模型的形式导出了相应的有效场论。随后,我们转向该模型的实验后果:涡旋核内部存在斯格明子,并且能够简洁地解释 B-T 相图。接下来,我们讨论第二个概念,即理论中的演生 U(1) 规范场。在这一更一般的框架内,赝能隙转变可被视为一种禁闭/退禁闭转变。我们研究了若干谱学探测手段的实验后果,包括非弹性中子散射、Raman 光谱、X 射线散射中的声子谱线以及角分辨光电子能谱实验。该理论表明,在铜氧化物相图中的适中温度下存在非相干玻色子,这些玻色子将在最佳掺杂处经历阻塞转变[1]。我们还考察了此类玻色子的存在对这些材料输运性质的影响。

英文摘要:

In this paper, we present our studies of the phase diagram of the cuprate superconductors performed in recent years. We describe how a few field-theoretical concepts can be used to account for the puzzling properties of these compounds. Starting with a short exposition of recent experimental developments, we then introduce the concept of an emergent SU(2) symmetry, which rotates between the superconducting and charge order parameters. We describe a solvable model for which this symmetry turns out to be exact and derive the corresponding effective field theory in terms of a non-linear σ model. We then turn to the experimental consequences of our model with the presence of skyrmions inside the vortex core and an elegant account of the B-T phase diagram. Next, we move on to the second concept, which is the one of an emergent U(1) gauge field in the theory. Within this more general framework, the pseudogap transition can be viewed as a confining/deconfining transition. Experimental consequences for a few spectroscopic probes like inelastic neutron scattering, Raman spectroscopy, phonon line in x-ray scattering and angle-resolved photoemission experiments are studied. This theory suggests the presence of incoherent bosons at moderate temperatures in the phase diagram of the cuprates, which would undergo a jamming transition at optimal doping [1]. Consequences of the presence of such bosons on the transport properties of these materials are examined.

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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