scholarly journals Dimension Effects in Insulating NbTiN Disordered Films and the Asymptotic Freedom of Cooper Pairs

JETP Letters ◽  
2019 ◽  
Vol 109 (12) ◽  
pp. 795-798
Author(s):  
M. V. Burdastyh ◽  
S. V. Postolova ◽  
I. A. Derbezov ◽  
A. V. Gaisler ◽  
M. C. Diamantini ◽  
...  
Keyword(s):  
Asymptotic Freedom ◽  
Cooper Pairs ◽  
Disordered Films

scholarly journals DIMENSION EffECTS IN INSULATING NBTIN DISORDERED fiLMS AND ASYMPTOTIC FREEDOM OF COOPER PAIRS

2019 ◽  
Vol 109 (11-12) ◽  
pp. 833-834
Author(s):  
M. V. BURDASTYH ◽  
S. V. POSTOLOVA ◽  
I. A. DERBEZOV ◽  
A. V. GAISLER ◽  
M. C. DIAMANTINI ◽  
...  
Keyword(s):  
Asymptotic Freedom ◽  
Cooper Pairs ◽  
Disordered Films

scholarly journals Confinement and asymptotic freedom with Cooper pairs

2018 ◽  
Vol 1 (1) ◽  
Author(s):  
M. C. Diamantini ◽  
C. A. Trugenberger ◽  
V. M. Vinokur
Keyword(s):  
Asymptotic Freedom ◽  
Cooper Pairs

scholarly journals Superinsulators: An Emergent Realisation of Confinement

Universe ◽  
2021 ◽  
Vol 7 (6) ◽  
pp. 201
Author(s):  
Maria Cristina Diamantini ◽  
Carlo A. Trugenberger
Keyword(s):  
Electric Fields ◽  
Bose Condensate ◽  
Meissner Effect ◽  
Magnetic Monopoles ◽  
Effective Field ◽  
Asymptotic Freedom ◽  
Cooper Pairs ◽  
Type Ii Superconductor ◽  
Topological State ◽  
Field Lines

Superinsulators (SI) are a new topological state of matter, predicted by our collaboration and experimentally observed in the critical vicinity of the superconductor-insulator transition (SIT). SI are dual to superconductors and realise electric-magnetic (S)-duality. The effective field theory that describes this topological phase of matter is governed by a compact Chern-Simons in (2+1) dimensions and a compact BF term in (3+1) dimensions. While in a superconductor the condensate of Cooper pairs generates the Meissner effect, which constricts the magnetic field lines penetrating a type II superconductor into Abrikosov vortices, in superinsulators Cooper pairs are linearly bound by electric fields squeezed into strings (dual Meissner effect) by a monopole condensate. Magnetic monopoles, while elusive as elementary particles, exist in certain materials in the form of emergent quasiparticle excitations. We demonstrate that at low temperatures magnetic monopoles can form a quantum Bose condensate (plasma in (2+1) dimensions) dual to the charge condensate in superconductors. The monopole Bose condensate manifests as a superinsulating state with infinite resistance, dual to superconductivity. The monopole supercurrents result in the electric analogue of the Meissner effect and lead to linear confinement of the Cooper pairs by Polyakov electric strings in analogy to quarks in hadrons. Superinsulators realise thus one of the mechanism proposed to explain confinement in QCD. Moreover, the string mechanism of confinement implies asymptotic freedom at the IR fixed point. We predict thus for superinsulators a metallic-like low temperature behaviour when samples are smaller than the string scale. This has been experimentally confirmed. We predict that an oblique version of SI is realised as the pseudogap state of high-TC superconductors.

Systems with Condensates and Pairing

2018 ◽  
Author(s):  
Klaus Morawetz
Keyword(s):  
Critical Parameters ◽  
Einstein Condensation ◽  
Cooper Pairs ◽  
Pair Breaking ◽  
Systematic Theory ◽  
Bose Einstein Condensation ◽  
T Matrix ◽  
The Stability ◽  
Bose Einstein

The Bose–Einstein condensation and appearance of superfluidity and superconductivity are introduced from basic phenomena. A systematic theory based on the asymmetric expansion of chapter 11 is shown to correct the T-matrix from unphysical multiple-scattering events. The resulting generalised Soven scheme provides the Beliaev equations for Boson’s and the Nambu–Gorkov equations for fermions without the usage of anomalous and non-conserving propagators. This systematic theory allows calculating the fluctuations above and below the critical parameters. Gap equations and Bogoliubov–DeGennes equations are derived from this theory. Interacting Bose systems with finite temperatures are discussed with successively better approximations ranging from Bogoliubov and Popov up to corrected T-matrices. For superconductivity, the asymmetric theory leading to the corrected T-matrix allows for establishing the stability of the condensate and decides correctly about the pair-breaking mechanisms in contrast to conventional approaches. The relation between the correlated density from nonlocal kinetic theory and the density of Cooper pairs is shown.

Parton models and asymptotic freedom

1974 ◽  
Vol 9 (12) ◽  
pp. 3391-3399 ◽  
Author(s):  
J. Kogut ◽  
Leonard Susskind
Keyword(s):  
Asymptotic Freedom

scholarly journals Multiplicity, Parity and Angular Momentum of a Cooper Pair in Unconventional Superconductors of D4h Symmetry: Sr2RuO4 and Fe-Pnictide Materials

Symmetry ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1435
Author(s):  
Victor G. Yarzhemsky
Keyword(s):  
Angular Momentum ◽  
Cooper Pair ◽  
Point Group ◽  
Group Symmetry ◽  
Cooper Pairs ◽  
Group Approach ◽  
Angular Momentum Projection ◽  
Space Group ◽  
Unconventional Superconductors ◽  
Even Pairs

Sr2RuO4 and Fe-pnictide superconductors belong to the same point group symmetry D4h. Many experimental data confirm odd pairs in Sr2RuO4 and even pairs in Fe-pnictides, but opposite conclusions also exist. Recent NMR results of Pustogow et al., which revealed even Cooper pairs in Sr2RuO4, require reconsideration of symmetry treatment of its SOP (superconducting order parameter). In the present work making use of the Mackey–Bradley theorem on symmetrized squares, a group theoretical investigation of possible pairing states in D4h symmetry is performed. It is obtained for I4/mmm , i.e., space group of Sr2RuO4, that triplet pairs with even spatial parts are possible in kz direction and in points M and Y. For the two latter cases pairing of equivalent electrons with nonzero total momentum is proposed. In P4/nmm space group of Fe- pnictides in point M, even and odd pairs are possible for singlet and triplet cases. It it shown that even and odd chiral states with angular momentum projection m=±1 have nodes in vertical planes, but Eg is nodal , whereas Eu is nodeless in the basal plane. It is also shown that the widely accepted assertion that the parity of angular momentum value is directly connected with the spatial parity of a pair is not valid in a space-group approach to the wavefunction of a Cooper pair.

scholarly journals On-demand thermoelectric generation of equal-spin Cooper pairs

2020 ◽  
Vol 2 (2) ◽  
Author(s):  
Felix Keidel ◽  
Sun-Yong Hwang ◽  
Björn Trauzettel ◽  
Björn Sothmann ◽  
Pablo Burset
Keyword(s):  
Cooper Pairs ◽  
Thermoelectric Generation ◽  
On Demand

scholarly journals Asymptotic freedom in quantum magnets

2015 ◽  
Vol 92 (22) ◽  
Author(s):  
H. D. Scammell ◽  
O. P. Sushkov
Keyword(s):  
Asymptotic Freedom ◽  
Quantum Magnets
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