scholarly journals Gate-tunable pairing channels in superconducting non-centrosymmetric oxides nanowires

2022 ◽  
Vol 7 (1) ◽  
Author(s):  
Gyanendra Singh ◽  
Claudio Guarcello ◽  
Edouard Lesne ◽  
Dag Winkler ◽  
Tord Claeson ◽  
...  
Keyword(s):  
Symmetry Breaking ◽  
Time Reversal ◽  
Inversion Symmetry ◽  
Unconventional Superconductivity ◽  
Magnetic Field Direction ◽  
Spin Orbit Coupling ◽  
Two Dimensional ◽  
Rashba Spin ◽  
Spin Singlet ◽  
The Magnetic Field

AbstractTwo-dimensional SrTiO3-based interfaces stand out among non-centrosymmetric superconductors due to their intricate interplay of gate-tunable Rashba spin-orbit coupling and multi-orbital electronic occupations, whose combination theoretically prefigures various forms of non-standard superconductivity. By employing superconducting transport measurements in nano-devices we present strong experimental indications of unconventional superconductivity in the LaAlO3/SrTiO3 interface. The central observations are the substantial anomalous enhancement of the critical current by small magnetic fields applied perpendicularly to the plane of electron motion, and the asymmetric response with respect to the magnetic field direction. These features cannot be accommodated within a scenario of canonical spin-singlet superconductivity. We demonstrate that the experimental observations can be described by a theoretical model based on the coexistence of Josephson channels with intrinsic phase shifts. Our results exclude a time-reversal symmetry breaking scenario and suggest the presence of anomalous pairing components that are compatible with inversion symmetry breaking and multi-orbital physics.

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.

Optical response of a two dimensional quantum ring in presence of Rashba spin orbit coupling

2016 ◽  
Vol 119 (7) ◽  
pp. 073101 ◽  
Author(s):  
Sukirti Gumber ◽  
Monica Gambhir ◽  
Pradip Kumar Jha ◽  
Man Mohan
Keyword(s):  
Optical Response ◽  
Orbit Coupling ◽  
Quantum Ring ◽  
Spin Orbit Coupling ◽  
Spin Orbit ◽  
Two Dimensional ◽  
Rashba Spin

scholarly journals Electronically driven spin-reorientation transition of the correlated polar metal Ca3Ru2O7

2020 ◽  
Vol 117 (27) ◽  
pp. 15524-15529 ◽  
Author(s):  
Igor Marković ◽  
Matthew D. Watson ◽  
Oliver J. Clark ◽  
Federico Mazzola ◽  
Edgar Abarca Morales ◽  
...  
Keyword(s):  
Symmetry Breaking ◽  
Sudden Onset ◽  
Spin Reorientation ◽  
Orbit Coupling ◽  
Inversion Symmetry ◽  
Spin Orbit Coupling ◽  
Spin Orbit ◽  
Large Hole ◽  
Electronic Correlations ◽  
Spin Reorientation Transition

The interplay between spin–orbit coupling and structural inversion symmetry breaking in solids has generated much interest due to the nontrivial spin and magnetic textures which can result. Such studies are typically focused on systems where large atomic number elements lead to strong spin–orbit coupling, in turn rendering electronic correlations weak. In contrast, here we investigate the temperature-dependent electronic structure ofCa3Ru2O7, a4doxide metal for which both correlations and spin–orbit coupling are pronounced and in which octahedral tilts and rotations combine to mediate both global and local inversion symmetry-breaking polar distortions. Our angle-resolved photoemission measurements reveal the destruction of a large hole-like Fermi surface upon cooling through a coupled structural and spin-reorientation transition at 48 K, accompanied by a sudden onset of quasiparticle coherence. We demonstrate how these result from band hybridization mediated by a hidden Rashba-type spin–orbit coupling. This is enabled by the bulk structural distortions and unlocked when the spin reorients perpendicular to the local symmetry-breaking potential at the Ru sites. We argue that the electronic energy gain associated with the band hybridization is actually the key driver for the phase transition, reflecting a delicate interplay between spin–orbit coupling and strong electronic correlations and revealing a route to control magnetic ordering in solids.

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