We use a concerted theory-experiment effort to investigate the formation of chiral real space spin texture when the archetypal Dirac semimetal ${\mathrm{Cd}}_3{\mathrm{As}}_2$ is interfaced with ${\mathrm{In}}_{1-x}{\mathrm{Mn}}_x\mathrm{As}$, a ferromagnetic semiconductor with perpendicular magnetic anisotropy. We combine density functional theory calculations, linear response theory for spin susceptibility and micromagnetic simulations to explore the possibility of chiral spin texture in this heterostructure. While a nonzero off-diagonal spin susceptibility in the ${\mathrm{Cd}}_3{\mathrm{As}}_2$ layer due to inversion symmetry breaking suggests the presence of Dzyaloshinskii-Moriya interaction (DMI) between local moments in the InMnAs layers, the amplitude may not be strong enough to give a “full” skyrmion texture. Instead, the interface states at the junction may promote a “partial” skyrmion texture. Using electrical magnetoresistance measurements at low temperature, we observe an emergent excess contribution to the transverse magnetoresistance whose behavior is consistent with a topological Hall effect arising from the formation of an interfacial chiral spin texture. This excess Hall voltage varies with gate voltage, indicating a promising electrostatically tunable platform for understanding the interplay between the helical momentum space states of a Dirac semimetal and chiral real-space spin textures in a ferromagnet.

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• Electronic structure
• Skyrmions
• Spin texture
• Dirac semimetal
• Topological materials
• First-principles calculations
• Molecular beam epitaxy