Anisotropic Josephson Coupling of d Vectors in Triplet Superconductors Arising from Frustrated Spin Textures

Abstract

We demonstrate that coupling itinerant electrons to a noncollinear classical exchange field can induce anisotropic Josephson coupling between superconducting d vectors, analogous to the Dzyaloshinskii-Moriya and Γ-type interactions in magnetism. Using perturbative methods, we analyze an s−d model on a geometrically frustrated lattice. Noncollinear local spin textures generate spin triplet pairing correlations and can favor spatially varying superconducting order due to anisotropic Josephson couplings between d vectors, endowing a “pliability” to the pairing order that competes with the superfluid stiffness. For nonunitary pairing, this spatial texture of d vectors can give rise to anomalous vortices in the absence of an external magnetic field. We further predict a Josephson diode effect with efficiency proportional to the spin chirality of the underlying magnetic texture. These results establish a link between frustrated magnetism and spatial textures of triplet superconducting pairing, with implications for a range of materials such as Mn3Ge and 4Hb−TaS2, where superconductivity can be proximity induced or intrinsic.

Source-reported materials — not catalogue approval

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