Magnetism-driven unconventional effects in Ising superconductors: role of proximity, tunneling, and nematicity

Abstract

Hybrid Ising superconductor-ferromagnetic insulator heterostructures provide a unique opportunity to explore the interplay between proximity-induced magnetism, spin-orbit coupling and superconductivity. Here we use a combination of first-principles calculations of NbSe${}_2$/CrBr${}_3$ heterostructures and an analytical theory of Ising superconductivity to analyze the existing experiments and provide a complete explanation of highly nontrivial and largely counterintuitive effects: an increase in the magnitude of the superconducting gap accompanied by the broadening of the tunneling peaks; hysteretic behavior of the tunneling conductance that sets in $\approx 2$ K below $T_c$; and nematic symmetry breaking in the superconducting state. The microscopic reason in all three cases appears to be the interplay between the proximity-induced exchange splitting and intrinsic defects. Finally, we predict additional interesting effects that at the moment cannot be addressed experimentally: spin-filtering when tunneling across CrBr${}_3$ and tunneling ``hot spots'' in momentum space that are anticorrelated with regions where the spin-orbit splitting is maximum.

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• Tailored tunnel magnetoresistance response in three ultrathin chromium trihalides
• Inhomogeneous time-reversal symmetry breaking in ${\mathrm{Sr}}_2\mathrm{Ru}{\mathrm{O}}_4$
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Cited by in corpus (12)

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• Mechanisms of the in-plane magnetic anisotropy in superconducting NbSe2
• Ising superconductivity: a first-principles perspective
• Gate-controlled proximity effect in superconductor/ferromagnet van der Waals heterostructures
• Magnetic proximity effect in superconductor/ferromagnet van der Waals heterostructures: dependence on the number of superconducting monolayers
• Gate-tunable nonlocal Josephson effect through magnetic van der Waals bilayers
• Unconventional pairing in Ising superconductors: Application to monolayer NbSe${}_2$
• Planar Hall effect from superconducting fluctuations
• Stacking of charge-density waves in 2H-NbSe${}_2$ bilayers
• Interplay of magnetic field and magnetic impurities in Ising superconductors
• Unconventional superconductivity in monolayer transition metal dichalcogenides
• Gate-Tunable Superconducting Spin Valve in a van der Waals Ferromagnet/Superconductor/Ferromagnet Trilayer