The role of the surface depression of the pair potential on the Josephson and quasi-particle tunnelling in high-T c superconductors

1994 ◽  
Vol 16 (12) ◽  
pp. 1979-1985
Author(s):  
R. S. Gonnelli ◽  
D. Puttero ◽  
G. A. Ummarino ◽  
V. A. Stepanov
Keyword(s):  
Pair Potential ◽  
Quasi Particle ◽  
Particle Tunnelling ◽  
Surface Depression

scholarly journals Graphene Domain Signature of Raman Spectra of sp2 Amorphous Carbons

Nanomaterials ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 2021
Author(s):  
Elena F. Sheka ◽  
Yevgeny A. Golubev ◽  
Nadezhda A. Popova
Keyword(s):  
Raman Spectra ◽  
Molecular Spectroscopy ◽  
Basic Structure ◽  
Quasi Particle ◽  
Phonon Spectra ◽  
2D Pattern ◽  
Density Delocalization ◽  
Electron Density Delocalization ◽  
High Degree

The standard D-G-2D pattern of Raman spectra of sp2 amorphous carbons is considered from the viewpoint of graphene domains presenting their basic structure units (BSUs) in terms of molecular spectroscopy. The molecular approximation allows connecting the characteristic D-G doublet spectra image of one-phonon spectra with a considerable dispersion of the C=C bond lengths within graphene domains, governed by size, heteroatom necklace of BSUs as well as BSUs packing. The interpretation of 2D two-phonon spectra reveals a particular role of electrical anharmonicity in the spectra formation and attributes this effect to a high degree of the electron density delocalization in graphene domains. A size-stimulated transition from molecular to quasi-particle phonon consideration of Raman spectra was experimentally traced, which allowed evaluation of a free path of optical phonons in graphene crystal.

scholarly journals Pattern Formation in One-Dimensional Polaron Systems and Temporal Orthogonality Catastrophe

Atoms ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 3
Author(s):  
Georgios M. Koutentakis ◽  
Simeon I. Mistakidis ◽  
Peter Schmelcher
Keyword(s):  
Ground State ◽  
Collective Excitation ◽  
Interspecies Interaction ◽  
Quasi Particle ◽  
Impurity Potential ◽  
One Dimensional ◽  
Zero Range ◽  
Dynamical Properties ◽  
The One

Recent studies have demonstrated that higher than two-body bath-impurity correlations are not important for quantitatively describing the ground state of the Bose polaron. Motivated by the above, we employ the so-called Gross Ansatz (GA) approach to unravel the stationary and dynamical properties of the homogeneous one-dimensional Bose-polaron for different impurity momenta and bath-impurity couplings. We explicate that the character of the equilibrium state crossovers from the quasi-particle Bose polaron regime to the collective-excitation stationary dark-bright soliton for varying impurity momentum and interactions. Following an interspecies interaction quench the temporal orthogonality catastrophe is identified, provided that bath-impurity interactions are sufficiently stronger than the intraspecies bath ones, thus generalizing the results of the confined case. This catastrophe originates from the formation of dispersive shock wave structures associated with the zero-range character of the bath-impurity potential. For initially moving impurities, a momentum transfer process from the impurity to the dispersive shock waves via the exerted drag force is demonstrated, resulting in a final polaronic state with reduced velocity. Our results clearly demonstrate the crucial role of non-linear excitations for determining the behavior of the one-dimensional Bose polaron.

scholarly journals Studying background processes of the exotic neutrino-nucleus reactions

2019 ◽  
Vol 21 ◽  
pp. 11
Author(s):  
D. K. Papoulias ◽  
T. S. Kosmas
Keyword(s):  
Charged Lepton ◽  
Neutral Current ◽  
New Physics ◽  
Quasi Particle ◽  
Leptonic Sector ◽  
Charged Leptons ◽  
Nuclear Structure Calculations ◽  
Structure Calculations ◽  
Lepton Flavour

The background processes of the flavour changing neutral current (FCNC) processes, predicted by various new-physics models to occur in the presence of nuclei, are examined by computing the relevant nuclear matrix elements within the context of the quasi-particle RPA using realistic strong two-body forces. Our main goal is to explore the role of the non-standard interactions (NSI) in the leptonic sector and specifically: (i) in lepton flavour violating (LFV) processes involving neutrinos νl and ν ̃l, l = e, μ, τ and (ii) in charged lepton flavour violating (cLFV) processes involving the charged leptons l− or l+. As concrete nuclear system we have chosen the stopping target of μ− → e− conversion experiment, i.e. the 48Ti nucleus of the PRIME/PRISM experiment at J-PARC. This experiment has been designed to reduce the single event sensitivity down to 10−16–10−18 in searching for charged lepton mixing events. We also present, stringent constraints on the flavour violating parameters entering the NSI Lagrangians that have been obtained by taking advantage of our detailed nuclear structure calculations and exploiting the present limits or the sensitivity of the proposed exotic μ− → e− experiments.

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