scholarly journals Neutrino Emission from Cooper Pairs at Finite Temperatures

2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Lev B. Leinson
Keyword(s):  
Weak Interactions ◽  
Neutrino Energy ◽  
Neutrino Emission ◽  
Cooper Pairs ◽  
Complete Suppression ◽  
Current State ◽  
Spin Singlet ◽  
Triplet Pairing ◽  
Spin Triplet ◽  
Neutrino Pair

A brief review is given of the current state of the problem of neutrino pair emission through neutral weak currents caused by the Cooper pairs breaking and formation (PBF) in superfluid baryon matter at thermal equilibrium. The cases of singlet-state pairing with isotropic superfluid gap and spin-triplet pairing with an anisotropic gap are analyzed with allowance for the anomalous weak interactions caused by superfluidity. It is shown that taking into account the anomalous weak interactions in both the vector and axial channels is very important for a correct description of neutrino energy losses through the PBF processes. The anomalous contributions lead to an almost complete suppression of the PBF neutrino emission in spin-singlet superfluids and strong reduction of the PBF neutrino losses in the spin-triplet superfluid neutron matter, which considerably slows down the cooling rate of neutron stars with superfluid cores.

scholarly journals Spin-orbit coupling suppression and singlet-state blocking of spin-triplet Cooper pairs

2021 ◽  
Vol 7 (3) ◽  
pp. eabe0128
Author(s):  
Sachio Komori ◽  
James M. Devine-Stoneman ◽  
Kohei Ohnishi ◽  
Guang Yang ◽  
Zhanna Devizorova ◽  
...  
Keyword(s):  
Orbit Coupling ◽  
Cooper Pairs ◽  
Triplet States ◽  
Spin Orbit Coupling ◽  
Spin Orbit ◽  
S Wave ◽  
Magnetic Exchange ◽  
Spin Singlet ◽  
Order Of Magnitude ◽  
Spin Triplet

An inhomogeneous magnetic exchange field at a superconductor/ferromagnet interface converts spin-singlet Cooper pairs to a spin-polarized triplet state. Although the decay envelope of triplet pairs within ferromagnetic materials is well studied, little is known about their decay in nonmagnetic metals and superconductors and, in particular, in the presence of spin-orbit coupling (SOC). Here, we investigate devices in which singlet and triplet supercurrents propagate into the s-wave superconductor Nb. In the normal state of Nb, triplet supercurrents decay over a distance of 5 nm, which is an order of magnitude smaller than the decay of spin-singlet pairs due to the SOC. In the superconducting state of Nb, triplet supercurrents are not able to couple with the singlet wave function and are thus blocked by the absence of available equilibrium states in the singlet gap. The results offer insight into the dynamics between s-wave singlet and s-wave triplet states.

ANALYSIS OF PROXIMITY EFFECTS BETWEEN SPIN SINGLET AND SPIN TRIPLET SUPERCONDUCTORS

1978 ◽  
Vol 39 (C6) ◽  
pp. C6-481-C6-483 ◽  
Author(s):  
K. Scharnberg ◽  
D. Fay ◽  
N. Schopohl
Keyword(s):  
Proximity Effects ◽  
Spin Singlet ◽  
Spin Triplet

scholarly journals Multiorbital singlet pairing and d + d superconductivity

2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Emilian M. Nica ◽  
Qimiao Si
Keyword(s):  
Time Reversal ◽  
Heavy Fermion ◽  
Degrees Of Freedom ◽  
Spin Orbit Coupling ◽  
Spin Orbit ◽  
Matrix Structure ◽  
Spin Singlet ◽  
Low Energies ◽  
Triplet Pairing ◽  
Orbital Space

AbstractRecent experiments in multiband Fe-based and heavy-fermion superconductors have challenged the long-held dichotomy between simple s- and d-wave spin-singlet pairing states. Here, we advance several time-reversal-invariant irreducible pairings that go beyond the standard singlet functions through a matrix structure in the band/orbital space, and elucidate their naturalness in multiband systems. We consider the sτ3 multiorbital superconducting state for Fe-chalcogenide superconductors. This state, corresponding to a d + d intra- and inter-band pairing, is shown to contrast with the more familiar d + id state in a way analogous to how the B- triplet pairing phase of 3He superfluid differs from its A- phase counterpart. In addition, we construct an analog of the sτ3 pairing for the heavy-fermion superconductor CeCu2Si2, using degrees-of-freedom that incorporate spin-orbit coupling. Our results lead to the proposition that d-wave superconductors in correlated multiband systems will generically have a fully-gapped Fermi surface when they are examined at sufficiently low energies.

Coexistence of spin-singlet s- and d-wave and spin-triplet p-wave order parameters in anisotropic superconductors

2007 ◽  
Vol 244 (10) ◽  
pp. 3559-3571 ◽  
Author(s):  
R. Gonczarek ◽  
M. Krzyzosiak ◽  
L. Jacak ◽  
A. Gonczarek
Keyword(s):  
Order Parameters ◽  
P Wave ◽  
Spin Singlet ◽  
Anisotropic Superconductors ◽  
Spin Triplet ◽  
D Wave

scholarly journals Giant Valley-Zeeman Splitting from Spin-Singlet and Spin-Triplet Interlayer Excitons in WSe2/MoSe2 Heterostructure

Nano Letters ◽  
2019 ◽  
Vol 20 (1) ◽  
pp. 694-700 ◽  
Author(s):  
Tianmeng Wang ◽  
Shengnan Miao ◽  
Zhipeng Li ◽  
Yuze Meng ◽  
Zhengguang Lu ◽  
...  
Keyword(s):  
Zeeman Splitting ◽  
Spin Singlet ◽  
Spin Triplet

scholarly journals Observation of half-quantum flux in the unconventional superconductor β-Bi2Pd

Science ◽  
2019 ◽  
Vol 366 (6462) ◽  
pp. 238-241 ◽  
Author(s):  
Yufan Li ◽  
Xiaoying Xu ◽  
M.-H. Lee ◽  
M.-W. Chu ◽  
C. L. Chien
Keyword(s):  
Magnetic Flux ◽  
Pairing Symmetry ◽  
Quantum Oscillation ◽  
Unconventional Superconductivity ◽  
Unconventional Superconductor ◽  
Quantum Bits ◽  
Flux Quantization ◽  
Triplet Pairing ◽  
Quantum Flux ◽  
Spin Triplet

Magnetic flux quantization is one of the defining properties of a superconductor. We report the observation of half-integer magnetic flux quantization in mesoscopic rings of superconducting β-Bi2Pd thin films. The half-quantum fluxoid manifests itself as a π phase shift in the quantum oscillation of the superconducting critical temperature. This result verifies unconventional superconductivity of β-Bi2Pd and is consistent with a spin-triplet pairing symmetry. Our findings may have implications for flux quantum bits in the context of quantum computing.

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