Orientational quadrupolar glass in ortho-para hydrogen mixtures. I. Mean-field microscopic theory

1996 ◽  
Vol 104 (1-2) ◽  
pp. 1-23 ◽  
Author(s):  
V. B. Kokshenev
Keyword(s):  
Mean Field ◽  
Microscopic Theory ◽  
Para Hydrogen ◽  
Hydrogen Mixtures ◽  
Quadrupolar Glass

ANOMALIES IN SPECIFIC HEAT: THE INFLUENCE OF SPIN FLUCTUATIONS AND SUPERCONDUCTIVITY IN CUPRATES

2013 ◽  
Vol 27 (13) ◽  
pp. 1350089 ◽  
Author(s):  
K. L. MOHANTA ◽  
G. C. ROUT
Keyword(s):  
Specific Heat ◽  
Cuprate Superconductors ◽  
Spin Fluctuation ◽  
Mean Field ◽  
Microscopic Theory ◽  
Spin Fluctuations ◽  
Function Technique ◽  
Transverse Spin ◽  
Model Parameters ◽  
Superconducting Transition

We report here a microscopic theory of the temperature dependence of specific heat in high-Tc cuprate superconductors. The system is described by a model Hamiltonian consisting the antiferromagnetic spin fluctuations due to the impurity f-electrons as well as the conduction electrons, besides the superconducting interaction due to the itinerant electrons. The Hamiltonian is treated within a mean-field approach. The transverse spin fluctuation parameters and the superconducting gap are calculated by Zubarev's Green's function technique and solved self-consistently. The temperature dependent specific heat is calculated from the free energy in order to study the anomalies appearing at the spin fluctuation and superconducting transition temperatures. The evolutions of these anomalies are studied by varying the model parameters of the systems and results are discussed in reference to experimental observations.

THE ANOMALIES IN SPECIFIC HEAT: THE INFLUENCE OF KONDO EFFECT AND f-ELECTRON CORRELATION IN HEAVY FERMION (HF) SYSTEMS

2012 ◽  
Vol 26 (30) ◽  
pp. 1250203 ◽  
Author(s):  
G. C. ROUT ◽  
P. C. BARAL
Keyword(s):  
Specific Heat ◽  
Electron Correlation ◽  
Heavy Fermion ◽  
Kondo Effect ◽  
Spin Exchange ◽  
Mean Field ◽  
Microscopic Theory ◽  
Spin Correlation ◽  
Mean Field Approximation ◽  
Model Parameters

We report here a microscopic theory of the temperature dependence of the specific heat in heavy fermion (HF) systems. The standard model Hamiltonian consists of c–f spin exchange term and Heisenberg type inter-site spin–spin correlation in addition to the conduction electron and f-electron hopping terms. The Hamiltonian is treated in mean-field approximation (MFA) taking into account two mean-field parameters i.e. the Kondo singlet [Formula: see text] and f-electron correlation parameter [Formula: see text]. An attempt has been made in this present communication to calculate the temperature dependent of specific heat to study the peaks at Kondo and correlation temperatures. The evolution of peaks are studied by varying the model parameters and comparing its relation to the experimental data.

RELATIVISTIC MEAN FIELD THEORY FOR UNSTABLE NUCLEI AND SUPERNOVAE

2003 ◽  
Vol 17 (28) ◽  
pp. 5175-5184
Author(s):  
HIROSHI TOKI
Keyword(s):  
Field Theory ◽  
Experimental Data ◽  
Equation Of State ◽  
Mean Field Theory ◽  
Mean Field ◽  
Microscopic Theory ◽  
Phenomenological Theory ◽  
Relativistic Mean Field ◽  
Unstable Nuclei ◽  
Finite Nuclei

We discuss first the properties of unstable nuclei in the framework of the relativistic mean field (RMF) theory. We take the RMF theory as a phenomenological theory with several parameters, whose form is constrained by the successful microscopic theory (RBHF), and whose values are extracted from the experimental data of unstable nuclei. We find the outcome with the use of the parameter sets (TM1 and TMA) is promising in comparison with various experimental data on finite nuclei including unstable ones. We construct then the equation of state of nuclear matter for the use in the description of supernovae. We present also the simulations of supernovae with the supernova newly constructed equation of state in the prompt explosion scenario.

Viscosity of ortho and para hydrogen mixtures

1973 ◽  
Vol 25 (2) ◽  
pp. 249-263 ◽  
Author(s):  
L. Monchick ◽  
N.J. Brown ◽  
R.J. Munn
Keyword(s):  
Para Hydrogen ◽  
Hydrogen Mixtures

Local ordering in dilute ortho-para-hydrogen mixtures at low temperatures

1988 ◽  
Vol 72 (1-2) ◽  
pp. 1-24 ◽  
Author(s):  
C. M. Edwards ◽  
D. Zhou ◽  
Y. Lin ◽  
N. S. Sullivan
Keyword(s):  
Low Temperatures ◽  
Para Hydrogen ◽  
Local Ordering ◽  
Hydrogen Mixtures
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