Magnetoelectric Andreev effect due to proximity-induced non-unitary triplet superconductivity in helical metals

Abstract

Non-centrosymmetric superconductors exhibit the magnetoelectric effect which manifests itself in the appearance of the magnetic spin polarization in response to a dissipationless electric current (supercurrent). While much attention has been dedicated to the thermodynamic version of this phenomenon (Edelstein effect), non-equilibrium transport magnetoelectric effects have not been explored yet. We propose the magnetoelectric Andreev effect (MAE) which consists in the generation of spin-polarized triplet Andreev conductance by an electric supercurrent. The MAE stems from the spin polarization of the Cooper-pair condensate due to a supercurrent-induced non-unitary triplet pairing. We propose the realization of such non-unitary pairing and MAE in superconducting proximity structures based on two-dimensional helical metals -- strongly spin-orbit-coupled electronic systems with the Dirac spectrum such as the topological surface states. Our results uncover an unexplored route towards electrically controlled superconducting spintronics and are a smoking gun for induced unconventional superconductivity in spin-orbit-coupled materials.

4.5 + 9 pages, 3 figures, version accepted by Physical Review Letters. Supplemental material includes discussion of a generic non-centrosymmetric superconductor

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Cited by in corpus (12)

• Superconducting phenomena in systems with unconventional magnets
• Tunable Anomalous Andreev Reflection and Triplet Pairings in Spin Orbit Coupled Graphene
• Nonlinear Superconducting Magnetoelectric Effect
• Nonunitary Superconductivity in Complex Quantum Materials
• Chiral current-phase relation of topological Josephson junctions: A signature of the $4\pi$-periodic Josephson effect
• Signature of Anomalous Andreev bound states in magnetic Josephson junction of noncentrosymmetric superconductor on a topological insulator
• Signatures of spin-triplet Cooper pairing in the density of states of spin-textured superconductor-ferromagnet bilayers
• Non-unitary multiorbital superconductivity from competing interactions in Dirac materials
• Stealth Majorana Zero Mode in a Trilayer Heterostructure MnTe/Bi2Te3/Fe(Te,Se)
• Magnetic exchange interaction in spin-valve with chiral spin-triplet superconductor
• Nonequilibrium Green's function approach to multi-band Cooper-pair transport: linear magnetoresistance effect due to nonunitary superconductivity
• Magnetization texture imprints produced by flux avalanches in ferromagnet/insulator/superconductor heterostructures