Exploring the Pseudogap in Cuprate Superconductors

2021 ◽  
Vol 1 ◽  
Keyword(s):  
High Temperature ◽  
Cuprate Superconductors ◽  
High Temperature Superconductivity ◽  
Degree Of Freedom ◽  
Crystal Symmetry ◽  
Oxide Materials ◽  
Potential Link

Electronic nematic correlation, in which electronic degree of freedom breaks the crystal symmetry, was found to have a potential link to the origin of high-temperature superconductivity in cooper oxide materials.

scholarly journals Unusual symmetries of the order parameter in cuprates

2020 ◽  
Vol 2 (4) ◽  
pp. 207-212
Author(s):  
Tran Van Luong ◽  
Nguyen Thi Ngoc Nu
Keyword(s):  
High Temperature ◽  
Order Parameter ◽  
Cuprate Superconductors ◽  
High Temperature Superconductivity ◽  
Spin Fluctuation ◽  
High Temperature Superconductors ◽  
Coulomb Repulsion ◽  
Bcs Theory ◽  
S Wave ◽  
Wave Symmetry

The BCS superconducting theory, introduced by J. Bardeen, L. Cooper and R. Schriffer in 1957, succeeded in describing and satis-factorily explaining the nature of superconductivity for low-temperature superconductors. However, the BCS theory cannot explain the properties of high-temperature superconductors, discovered by J. G. Bednorz and K. A. Müller in 1986. Although scientists have found a lot of new superconductors and their transition temperatures are constantly increasing, most high-temperature superconductors are found by experiment and so far no theory can fully explain their properties. Many previous studies have suggested that the order parameter in high-temperature copper-based superconductors (cuprate superconductors - cuprates) is in the form of d-wave symmetry, but recent results show that the order parameter has an extended s-wave symmetry (extended s wave). Studying the symmetric forms of order parameters in cuprate can contribute to understanding the nature of high-temperature superconductivity. In this article, the authors present an overview of the development of high-temperature supercon-ductors over the past 30 years and explains unusual symmetries of the order parameter in copper-based superconductors. The com-petition of three coupling mechanisms of electrons in cuprates (the mechanism of coupling through coulomb repulsion, electron-phonon mechanism and spin-fluctuation mechanism) affects the unusual symmetry of the order parameter. The solution of the self-consistency equation in simple cases has been found and the ability to move the phase within the superconducting state has been shown.

scholarly journals RAMAN SCATTERING IN IRON-BASED SUPERCONDUCTORS

2012 ◽  
Vol 26 (28) ◽  
pp. 1230020 ◽  
Author(s):  
A. M. ZHANG ◽  
Q. M. ZHANG
Keyword(s):  
High Temperature ◽  
Raman Scattering ◽  
Cuprate Superconductors ◽  
High Temperature Superconductivity ◽  
Industrial Applications ◽  
Layered Compounds ◽  
Correlated Electron Systems ◽  
Correlated Electron ◽  
History Of ◽  
Iron Based

Iron-based superconducting layered compounds have the second highest transition temperature after cuprate superconductors. Their discovery is a milestone in the history of high-temperature superconductivity and will have profound implications for high-temperature superconducting mechanism as well as industrial applications. Raman scattering has been extensively applied to correlated electron systems including the new superconductors due to its unique ability to probe multiple primary excitations and their coupling. In this review, we will give a brief summary of the existing Raman experiments in the iron-based materials and their implications for pairing mechanism in particular. And we will also address some open issues from the experiments.

The Mysteries of Charge Order and Charge Fluctuations in Cuprate Superconductors

2021 ◽  
Vol 1 ◽  
Keyword(s):  
High Temperature ◽  
Cuprate Superconductors ◽  
High Temperature Superconductivity ◽  
Charge Order ◽  
Charge Fluctuations

This Special Topics issue condenses the latest research on the enigmatic characteristics of high-temperature superconductivity in cuprates through the observation and elucidation of charge order, charge fluctuations, and other phenomena.

scholarly journals Fluctuations and the Higgs Mechanism in Underdoped Cuprates

2020 ◽  
Vol 11 (1) ◽  
pp. 301-323 ◽  
Author(s):  
C. Pépin ◽  
D. Chakraborty ◽  
M. Grandadam ◽  
S. Sarkar
Keyword(s):  
High Temperature ◽  
Cuprate Superconductors ◽  
High Temperature Superconductivity ◽  
Higgs Mechanism ◽  
Pseudogap Phase ◽  
Theoretical Approaches ◽  
Underdoped Region ◽  
Underdoped Cuprates ◽  
The Rich ◽  
Ubiquitous Presence

The physics of the pseudogap phase of high-temperature cuprate superconductors has been an enduring mystery over the past 30 years. The ubiquitous presence of the pseudogap phase in underdoped cuprates suggests that understanding it is key to unraveling the origin of high-temperature superconductivity. We review various theoretical approaches to this problem, emphasizing the concept of emergent symmetries in the underdoped region of those compounds. We differentiate these theories by considering a few fundamental questions related to the rich phenomenology of these materials. Lastly, we discuss a recent idea regarding two kinds of entangled preformed pairs that open a gap at the pseudogap onset temperature, T*, through a specific Higgs mechanism. We review the experimental consequences of this line of thought.

THE EVOLUTION OF HIGH-TEMPERATURE SUPERCONDUCTIVITY: THEORY PERSPECTIVE

2010 ◽  
Vol 24 (20n21) ◽  
pp. 4150-4180 ◽  
Author(s):  
Elihu Abrahams
Keyword(s):  
High Temperature ◽  
Transition Temperature ◽  
Cuprate Superconductors ◽  
High Temperature Superconductivity ◽  
High Transition Temperature ◽  
High Transition ◽  
Superconductivity Theory ◽  
Theoretical Developments

Theoretical developments concerning the high transition temperature cuprate superconductors are reviewed.

scholarly journals Local Electron-Lattice Interactions in High-Temperature Cuprate Superconductors

2010 ◽  
Vol 2010 ◽  
pp. 1-17 ◽  
Author(s):  
Hugo Keller ◽  
Annette Bussmann-Holder
Keyword(s):  
High Temperature ◽  
Cuprate Superconductors ◽  
High Temperature Superconductivity ◽  
Isotope Effects ◽  
Multiband Superconductivity ◽  
Local Electron ◽  
Layered Superconductors ◽  
Two Component ◽  
Local Lattice

Recent experimental observations of unconventional isotope effects, multiband superconductivity, and unusual local lattice responses are reviewed and shown to be naturally explained within a two-component scenario where local polaronic effects are important. It is concluded that purely electronic mechanisms of high-temperature superconductivity are incomplete and unable to capture the essential physics of cuprates and other layered superconductors.

ELECTRONIC RAMAN SCATTERING IN CUPRATE SUPERCONDUCTORS

2013 ◽  
Vol 27 (09) ◽  
pp. 1330006
Author(s):  
ZHIHAO GENG ◽  
SHIPING FENG
Keyword(s):  
High Temperature ◽  
Raman Scattering ◽  
Cuprate Superconductors ◽  
High Temperature Superconductivity ◽  
Cooper Pairs ◽  
Electronic Excitations ◽  
Temperature Dependent ◽  
Electronic Raman Scattering ◽  
Raman Response ◽  
Theoretical Results

Since the discovery of cuprate superconductors, the mechanism of high temperature superconductivity is still a mystery. Among the investigation tools, the electronic Raman scattering is a powerful one to probe electronic excitations in different regions of the Fermi surface of cuprate superconductors by a simple choice of the incident and scattered polarization vectors. Thus the symmetry of the superconducting Cooper pairs can be indicated. In this article we review our investigations of electronic Raman scattering in cuprate superconductors based on the t–J model within the kinetic energy driven superconductivity. The theory of electronic Raman response in cuprate superconductors is presented together with an overview of the charge-spin separation fermion-spin theory to handle the t–J model. Some theoretical results of electronic Raman response are presented in comparison with the experimental results. Special emphasize is given to the doping and temperature dependent of electronic Raman spectra.

FIELD-INDUCED ANTIFERROMAGNETISM IN THE HIGH-TEMPERATURE SUPERCONDUCTOR La2-xSrxCuO4

2002 ◽  
Vol 16 (20n22) ◽  
pp. 3197-3197
Author(s):  
B. LAKE ◽  
T. E. MASON ◽  
G. AEPPLI ◽  
K. LEFMANN ◽  
N. B. CHRISTENSEN ◽  
...  
Keyword(s):  
Magnetic Field ◽  
High Temperature ◽  
Normal State ◽  
Cuprate Superconductors ◽  
High Temperature Superconductivity ◽  
Field Measurements ◽  
Spin Fluctuations ◽  
Magnetic Interactions ◽  
Zero Field ◽  
Zero Resistance

There is strong evidence that magnetic interactions play a crucial role in the mechanism driving high-temperature superconductivity in cuprate superconductors. To investigate this we have done a series of neutron scattering measurements on La 2-x Sr x CuO 4 (LSCO) in an applied magnetic field. Below Tc the field penetrates the superconductor via an array of normal state metallic inclusions or vortices. Phase coherent superconductivity characterized by zero resistance sets in at the lower field-dependent irreversibility temperature (Tirr). We have measured optimally doped LSCO (x = 0.16, Tc = 38.5 K ) and under-doped LSCO ( x = 0.10, Tc = 29 K ); both have an enhanced antiferromagnetic response in a field. Measurements of the optimally doped system at H = 7.5 T show that sub-gap spin fluctuations first disappear with the loss of finite resistivity at Tirr, but then reappear at a lower temperature with increased lifetime and correlation length compared to the normal state. In the under-doped system elastic antiferromagnetism develops below Tc in zero field, and is significantly enchanced by application of a magnetic field. Phase coherent superconductivity is then established within the antiferromagnetic phase at Tirr; thus, the situation in under-doped LSCO is the reverse of that for the optimally doped LSCO where the zero-resistance state develops first before the onset of antiferromagnetism.

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