On the relationship between doping, critical temperatures and pressure gradients of Tc in high-Tc cuprates: The double role of oxygen

1992 ◽  
Vol 201 (3-4) ◽  
pp. 295-304 ◽  
Author(s):  
Laurens Jansen ◽  
Leena Chandran ◽  
Ruud Block
Keyword(s):  
Pressure Gradients ◽  
Critical Temperatures ◽  
High Tc ◽  
The Relationship ◽  
High Tc Cuprates

scholarly journals Analytical Descriptions of High-Tc Cuprates by Introducing Rotating Holes and a New Model to Handle Many-Body Interactions

2020 ◽  
Author(s):  
Shinichi Ishiguri
Keyword(s):  
Metal Phase ◽  
Field Energy ◽  
Many Body ◽  
Critical Temperatures ◽  
High Tc ◽  
New Model ◽  
Magnetic Field Energy ◽  
Statistic Model ◽  
Many Body Interactions ◽  
High Tc Cuprates

This paper describes all the properties of high-Tc cuprates by introducing rotating holes which are created by angular momentum conservations on a two dimensional CuO2 surface, and which have a different mass from that of a normal hole due to the magnetic field energy induced by the rotation. This new particle called a macroscopic boson describes doping dependences of pseudo gap temperature and the transition temperature at which an anomaly metal phase appears. In addition, it also describes all the properties of the anomaly metal phase, using findings from our previous article [1] . Furthermore, the present paper introduces a new model to handle many-body interactions, which results in a new statistic equation. A partition function of macroscopic bosons describes all the properties of the anomaly metal phase, which sufficiently agrees with experiments. Moreover, the above-mentioned statistic equation describing many-body interactions accurately explains why high-Tc cuprates have significantly high critical temperatures, which indicates that the source of the characteristic stems from pseudo gap energy. By introducing a macroscopic boson and the new statistic model for many-body interactions, the present paper uncovered the mystery of high-Tc cuprates, which have been a challenge for many researchers. Moreover, in the present paper, pure analytical calculations are conducted. These calculations agree with experimental data which do not employ numerical calculations or fitting methods but employ many actual physical constants.

scholarly journals The possible role of van Hove singularities in the high Tc of superconducting H3S

2017 ◽  
Vol 31 (25) ◽  
pp. 1745003 ◽  
Author(s):  
Thiago X. R. Souza ◽  
F. Marsiglio
Keyword(s):  
Analytical Solution ◽  
Entire Range ◽  
Nearest Neighbor ◽  
Zero Energy ◽  
Critical Temperatures ◽  
High Tc ◽  
Electron Density Of States ◽  
Bcc Structure ◽  
Coupling Strengths

We observe that H3S has a BCC structure and, with nearest neighbor hopping only, a strong singularity occurs at zero energy. This singularity is accompanied with a highly nested Fermi surface, which is not conducive to a stable superconducting instability. Introduction of next-nearest-neighbor hopping removes the singularity, but a “robust” peak remains in the electron density of states. Solution of the BCS equations shows an enhanced superconducting [Formula: see text] due to this peak. Furthermore, nesting is no longer present, so other instabilities will not compete effectively with superconductivity. We find high critical temperatures are possible, even with very modest coupling strengths. We also examine a limit of the [Formula: see text] equations (in an Appendix) where an analytical solution is possible over the entire range of coupling strengths, and therefore the BCS-BEC crossover is fully covered.

The role of doping and pressure in Hg based high Tc cuprates: A theoretical study

2008 ◽  
Vol 8 (2) ◽  
pp. 149-152 ◽  
Author(s):  
C. Ambrosch-Draxl ◽  
T. Thonhauser ◽  
E.Ya. Sherman
Keyword(s):  
Theoretical Study ◽  
High Tc ◽  
High Tc Cuprates

scholarly journals The Mechanism of Electrolyte Gating on High-Tc Cuprates: The Role of Oxygen Migration and Electrostatics

ACS Nano ◽  
2017 ◽  
Vol 11 (10) ◽  
pp. 9950-9956 ◽  
Author(s):  
Lingchao Zhang ◽  
Shengwei Zeng ◽  
Xinmao Yin ◽  
Teguh Citra Asmara ◽  
Ping Yang ◽  
...  
Keyword(s):  
High Tc ◽  
Electrolyte Gating ◽  
Oxygen Migration ◽  
High Tc Cuprates

The role of epitaxial strain in the properties of high Tc thin films

1995 ◽  
Vol 53 ◽  
pp. 382-383
Author(s):  
E.J. Williams ◽  
A. Cretton ◽  
Y. Jaccard ◽  
J.-P. Locquet ◽  
E. Mächler ◽  
...  
Keyword(s):  
Thin Films ◽  
Bulk Material ◽  
Kinetic Inductance ◽  
Film Material ◽  
X Ray Diffraction ◽  
Critical Temperatures ◽  
High Tc ◽  
Epitaxial Strain ◽  
The Difference

The difference observed between the critical temperatures measured for bulk material or very thick films (> 500 nm for the ‘214’ system) and those measured for thin films (< 65 nm) has long been of curiosity. Thin films never attain the high values of Tc achieved in bulk or thick film material. Various mechanisms have been proposed to explain this phenomenon, for example Kosterlitz-Thouless effects, inadequate or unstable oxygenation, and strain itself. Formally the role of strain has remained insubstantiated.The system on which we have concentrated our efforts is that of La2-xSrxCuO4 (LSCO) deposited using MBE, mainly onto (001) SrTiO3 (STO) substrates. These films have been grown at about 700°C at ~3 × 10-6 torr oxygen pressure and cooled after growth at -10° min-1. The films have subsequently been examined using several microstructural and electronic probes, including x-ray diffraction, AFM, resistivity, Hall effect and kinetic inductance.

scholarly journals Analytical Descriptions of High Tc Cuprates by Introducing Rotating Holes and a New Model to Handle Many-Body Interactions

2020 ◽  
Author(s):  
Shinichi Ishiguri
Keyword(s):  
Metal Phase ◽  
Field Energy ◽  
Many Body ◽  
Critical Temperatures ◽  
High Tc ◽  
New Model ◽  
Magnetic Field Energy ◽  
Many Body Interactions ◽  
The Magnetic Field ◽  
High Tc Cuprates

This study describes all the properties of high Tc cuprates by introducing rotating holes that are created by angular momentum conservations on a 2D CuO2 surface, and which have a different mass from that of a normal hole because of the magnetic field energy induced by the rotation. This new particle called a macroscopic Boson describes the doping dependences of pseudo-gap temperature and the transition temperature at which an anomaly metal phase appears and describes the origin of the pseudo-gap. Furthermore, this study introduces a new model to handle many-body interactions, which results in a new statistic equation. This statistic equation describing many-body interactions accurately explains why high Tc cuprates have significantly high critical temperatures. Moreover a partition function of macroscopic Bosons describes all the properties of anomaly metal phase, which sufficiently agree with experiments, using the result from our previous study [1] that analytically describes the doping dependence of Tc. By introducing a macroscopic Boson and the new statistical model for many-body interactions, this study uncovered the mystery of high Tc cuprates, which have been a challenge for many researchers. An important point is that, in this study, pure analytical calculations are consistently conducted, which agree with experimental data well (i.e., they do not use numerical calculations or fitting methods but use many actual physical constants).

Choosing a Markov blanket

2020 ◽  
Vol 43 ◽  
Author(s):  
Thomas Parr
Keyword(s):  
Markov Blanket ◽  
Target Article ◽  
The Relationship

Abstract This commentary focuses upon the relationship between two themes in the target article: the ways in which a Markov blanket may be defined and the role of precision and salience in mediating the interactions between what is internal and external to a system. These each rest upon the different perspectives we might take while “choosing” a Markov blanket.

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