scholarly journals Normal and superconducting state in the presence of forward electron-phonon and impurity scattering

1999 ◽  
Vol 9 (2) ◽  
pp. 201-206 ◽  
Author(s):  
O.V. Danylenko ◽  
O.V. Dolgov ◽  
M.L. Kulic ◽  
V. Oudovenko
Keyword(s):  
Superconducting State ◽  
Impurity Scattering

scholarly journals Self-consistent solution for the magnetic exchange interaction mediated by a superconductor

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Atousa Ghanbari ◽  
Vetle K. Risinggård ◽  
Jacob Linder
Keyword(s):  
Exchange Interaction ◽  
Superconducting State ◽  
Ground State ◽  
Tight Binding ◽  
Impurity Scattering ◽  
Superconducting Gap ◽  
Condensation Energy ◽  
Magnetic Exchange Interaction ◽  
Magnetic Exchange ◽  
Parallel Configuration

AbstractWe theoretically determine the magnetic exchange interaction between two ferromagnets coupled by a superconductor using a tight-binding lattice model. The main purpose of this study is to determine how the self-consistently determined superconducting state influences the exchange interaction and the preferred ground-state of the system, including the role of impurity scattering. We find that the superconducting state eliminates RKKY-like oscillations for a sufficiently large superconducting gap, making the anti-parallel orientation the ground state of the system. Interestingly, the superconducting gap is larger in the parallel configuration than in the anti-parallel configuration, giving a larger superconducting condensation energy, even when the preferred ground state is anti-parallel. We also show that increasing the impurity concentration in the superconductor causes the exchange interaction to decrease, likely due to an increasing localization of the mediating quasiparticles in the superconductor.

scholarly journals Quasiparticle Lifetimes and the Conductivity Scattering Rate

1997 ◽  
Vol 50 (6) ◽  
pp. 1011 ◽  
Author(s):  
F. Marsiglio ◽  
J. P. Carbotte
Keyword(s):  
Fermi Surface ◽  
Single Particle ◽  
Superconducting State ◽  
Qualitative Agreement ◽  
Impurity Scattering ◽  
Quantitative Agreement ◽  
Metallic System ◽  
S Wave ◽  
Scattering Rate ◽  
Quasiparticle Lifetime

We compute the single-particle inverse lifetime, along with the conductivity-derived scattering rate, for a metallic system in an s-wave superconducting state. When both electron–phonon and electron-impurity scattering are included, we find that while these scattering rates are in qualitative agreement, in general quantitative agreement is lacking. We also derive results for the quasiparticle lifetime within the BCS framework with impurity scattering, which makes it clear that impurity scattering is suppressed for electrons near the Fermi surface in the superconducting state.

Observation by HVEM of the martensite transformation and the superconducting transition in Nb3Sn

1988 ◽  
Vol 46 ◽  
pp. 788-789
Author(s):  
M. A. Kirk ◽  
M. C. Baker ◽  
B. J. Kestel ◽  
H. W. Weber
Keyword(s):  
Thin Films ◽  
Low Temperature ◽  
Superconducting State ◽  
Martensite Transformation ◽  
Sputter Deposition ◽  
Diffusion Reaction ◽  
Solute Diffusion ◽  
Superconducting Transition ◽  
Twin Boundaries ◽  
Martensite Structure

It is well known that a number of compound superconductors with the A15 structure undergo a martensite transformation when cooled to the superconducting state. Nb3Sn is one of those compounds that transforms, at least partially, from a cubic to tetragonal structure near 43 K. To our knowledge this transformation in Nb3Sn has not been studied by TEM. In fact, the only low temperature TEM study of an A15 material, V3Si, was performed by Goringe and Valdre over 20 years ago. They found the martensite structure in some foil areas at temperatures between 11 and 29 K, accompanied by faults that consisted of coherent twin boundaries on {110} planes. In pursuing our studies of irradiation defects in superconductors, we are the first to observe by TEM a similar martensite structure in Nb3Sn.Samples of Nb3Sn suitable for TEM studies have been produced by both a liquid solute diffusion reaction and by sputter deposition of thin films.

Deep Impurities with Collision Delay

2018 ◽  
Author(s):  
Klaus Morawetz
Keyword(s):  
Wave Function ◽  
Kinetic Equation ◽  
Elastic Scattering ◽  
Response Function ◽  
Plasma Oscillation ◽  
Impurity Scattering ◽  
Fermi Momentum ◽  
Screening Length ◽  
Plasma Mode ◽  
Dissipative Mechanism

The linearised nonlocal kinetic equation is solved analytically for impurity scattering. The resulting response function provides the conductivity, plasma oscillation and Fermi momentum. It is found that virial corrections nearly compensate the wave-function renormalizations rendering the conductivity and plasma mode unchanged. Due to the appearance of the correlated density, the Luttinger theorem does not hold and the screening length is influenced. Explicit results are given for a typical semiconductor. Elastic scattering of electrons by impurities is the simplest but still very interesting dissipative mechanism in semiconductors. Its simplicity follows from the absence of the impurity dynamics, so that individual collisions are described by the motion of an electron in a fixed potential.

scholarly journals Effect of Oxygen Source on the Various Properties of SnO2 Thin Films Deposited by Plasma-Enhanced Atomic Layer Deposition

Coatings ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 692
Author(s):  
Jong Hyeon Won ◽  
Seong Ho Han ◽  
Bo Keun Park ◽  
Taek-Mo Chung ◽  
Jeong Hwan Han
Keyword(s):  
Electrical Properties ◽  
Atomic Layer Deposition ◽  
Carrier Concentration ◽  
High Mobility ◽  
Impurity Scattering ◽  
Atomic Layer ◽  
Growth Behavior ◽  
Layer Deposition ◽  
Growth Feature ◽  
O2 Plasma

Herein, we performed a comparative study of plasma-enhanced atomic layer deposition (PEALD) of SnO2 films using Sn(dmamp)2 as the Sn source and either H2O plasma or O2 plasma as the oxygen source in a wide temperature range of 100–300 °C. Since the type of oxygen source employed in PEALD determines the growth behavior and resultant film properties, we investigated the growth feature of both SnO2 PEALD processes and the various chemical, structural, morphological, optical, and electrical properties of SnO2 films, depending on the oxygen source. SnO2 films from Sn(dmamp)2/H2O plasma (SH-SnO2) and Sn(dmamp)2/O2 plasma (SO-SnO2) showed self-limiting atomic layer deposition (ALD) growth behavior with growth rates of ~0.21 and 0.07–0.13 nm/cycle, respectively. SO-SnO2 films showed relatively larger grain structures than SH-SnO2 films at all temperatures. Interestingly, SH-SnO2 films grown at high temperatures of 250 and 300 °C presented porous rod-shaped surface morphology. SO-SnO2 films showed good electrical properties, such as high mobility up to 27 cm2 V−1·s−1 and high carrier concentration of ~1019 cm−3, whereas SH-SnO2 films exhibited poor Hall mobility of 0.3–1.4 cm2 V−1·s−1 and moderate carrier concentration of 1 × 1017–30 × 1017 cm−3. This may be attributed to the significant grain boundary and hydrogen impurity scattering.

scholarly journals Specific heat of Zn-dopedYBa2Cu3O6.95:Possible evidence for Kondo screening in the superconducting state

2000 ◽  
Vol 61 (5) ◽  
pp. 3604-3609 ◽  
Author(s):  
D. L. Sisson ◽  
S. G. Doettinger ◽  
A. Kapitulnik ◽  
R. Liang ◽  
D. A. Bonn ◽  
...  
Keyword(s):  
Specific Heat ◽  
Superconducting State ◽  
Kondo Screening

scholarly journals Chiral topological superconducting state with Chern number C = −2 in Pb3Bi/Ge(111)

2021 ◽  
Vol 103 (23) ◽  
Author(s):  
Shuwen Sun ◽  
Wei Qin ◽  
Leiqiang Li ◽  
Zhenyu Zhang
Keyword(s):  
Superconducting State ◽  
Chern Number
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