The R dependence of the phase diagram of Bi2Sr2−xRxCuOy and its implication on high temperature superconductivity

It is important to understand the phase diagram of electronic states in the CuO2 plane to clarify the mechanism of high-temperature superconductivity. We investigate the ground state of electronic models with strong correlation by employing the optimization variational Monte Carlo method. We consider the two-dimensional Hubbard model as well as the three-band [Formula: see text]–[Formula: see text] model. We use the improved wave function that takes account of inter-site electron correlation to go beyond the Gutzwiller wave function. The ground state energy is lowered considerably, which now gives the best estimate of the ground state energy for the two-dimensional Hubbard model. The many-body effect plays an important role as an origin of spin correlation and superconductivity in correlated electron systems. We investigate the competition between the antiferromagnetic state and superconducting state by varying the Coulomb repulsion [Formula: see text], the band parameter [Formula: see text] and the electron density [Formula: see text] for the Hubbard model. We show phase diagrams that include superconducting and antiferromagnetic phases. We expect that high-temperature superconductivity occurs near the boundary between antiferromagnetic phase and superconducting one. Since the three-band [Formula: see text]–[Formula: see text] model contains many-band parameters, high-temperature superconductivity may be more likely to occur in the [Formula: see text]–[Formula: see text] model than in single-band models.

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Structural and magnetic phase diagram of CeFeAsO1− xFx and its relation to high-temperature superconductivity

Nature Materials ◽

10.1038/nmat2315 ◽

2008 ◽

Vol 7 (12) ◽

pp. 953-959 ◽

Cited By ~ 633

Author(s):

Jun Zhao ◽

Q. Huang ◽

Clarina de la Cruz ◽

Shiliang Li ◽

J. W. Lynn ◽

...

Keyword(s):

Phase Diagram ◽

High Temperature ◽

High Temperature Superconductivity ◽

Magnetic Phase ◽

Magnetic Phase Diagram

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Phase Diagram and High-Temperature Superconductivity of Compressed Selenium Hydrides

Scientific Reports ◽

10.1038/srep15433 ◽

2015 ◽

Vol 5 (1) ◽

Cited By ~ 44

Author(s):

Shoutao Zhang ◽

Yanchao Wang ◽

Jurong Zhang ◽

Hanyu Liu ◽

Xin Zhong ◽

...

Keyword(s):

Phase Diagram ◽

High Temperature ◽

High Temperature Superconductivity

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How Is the Zero-Resistance of the Superconductor Generated and Is the Phase Diagram of the High-Temperature Superconductivity Explained

Advances in Condensed Matter Physics ◽

10.12677/cmp.2014.32002 ◽

2014 ◽

Vol 03 (02) ◽

pp. 5-21

Author(s):

秀园胡

Keyword(s):

Phase Diagram ◽

High Temperature ◽

High Temperature Superconductivity ◽

Zero Resistance

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Experimental Study and Thermodynamic Calculation of BaO-Lu2O3 Binary System

Materials Science Forum ◽

10.4028/www.scientific.net/msf.852.443 ◽

2016 ◽

Vol 852 ◽

pp. 443-448 ◽

Cited By ~ 1

Author(s):

Xin Yu Ye ◽

Qin Li ◽

Yang Luo ◽

Di Wu

Keyword(s):

Phase Diagram ◽

High Temperature ◽

Binary System ◽

Gibbs Energy ◽

High Temperature Superconductivity ◽

Intermediate Phase ◽

Calculated Phase Diagram ◽

Intermediate Compound ◽

Experimental Phase Diagram ◽

Metallurgical Slags

Only one intermediate compound Ba3Lu4O9was identified at 1373, 1573 and 1773K in the BaO-Lu2O3system in present work.Based on the available experimental phase diagram and relevant thermodynamic data, BaO-Lu2O3 binary system was optimized and calculated by using CALPHAD method. The Gibbs free energy of high temperature solution was described by an ionic two-sublattice model as (Ba2+,Lu3+)P(O2-)Q. The calculated phase diagram, Gibbs energy of intermediate phase Ba3Lu4O9and Gibbs energy of mixingagreewell with experimental resultswithin error limits. The study will offer theoretical basis for further research of the phosphor matrix system of BaO-Lu2O3-SiO2, but also provide new idea for the phase diagram and thermodynamic research on related metallurgical slags, refractories, high-temperature superconductivity material systems.

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High-temperature superconductivity in sulfur hydride evidenced by alternating-current magnetic susceptibility

National Science Review ◽

10.1093/nsr/nwz061 ◽

2019 ◽

Vol 6 (4) ◽

pp. 713-718 ◽

Cited By ~ 8

Author(s):

Xiaoli Huang ◽

Xin Wang ◽

Defang Duan ◽

Bertil Sundqvist ◽

Xin Li ◽

...

Keyword(s):

Phase Diagram ◽

Magnetic Susceptibility ◽

High Temperature ◽

High Temperature Superconductivity ◽

Theoretical Calculations ◽

Meissner Effect ◽

Alternating Current ◽

Superconducting Phase ◽

Electron Phonon Interaction

ABSTRACT The search for high-temperature superconductivity is one of the research frontiers in physics. In the sulfur hydride system, an extremely high Tc (∼200 K) has been recently developed at pressure. However, the Meissner effect measurement above megabar pressures is still a great challenge. Here, we report the superconductivity identification of sulfur hydride at pressure, employing an in situ alternating-current magnetic susceptibility technique. We determine the superconducting phase diagram, finding that superconductivity suddenly appears at 117 GPa and Tc reaches 183 K at 149 GPa before decreasing monotonically with increasing pressure. By means of theoretical calculations, we elucidate the variation of Tc in the low-pressure region in terms of the changing stoichiometry of sulfur hydride and the further decrease in Tc owing to a drop in the electron–phonon interaction parameter λ. This work provides a new insight into clarifying superconducting phenomena and anchoring the superconducting phase diagram in the hydrides.

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