# Rashba spin splitting-induced topological Hall effect in a Dirac semimetal-ferromagnetic semiconductor heterostructure

**Authors:** Saurav Islam, Emma Steinebronn, Kaijie Yang, Bimal Neupane, Juan Chamorro, Supriya Ghosh, K. Andre Mkhoyan, Tyrel M. McQueen, Yuanxi Wang, Chaoxing Liu, Nitin Samarth  
**arXiv:** [2403.18485](https://arxiv.org/abs/2403.18485)  
**Date:** 2024-03-27  
**Summary page:** https://www.summarizepaper.com/fr/paper/2403.18485v1/

## Abstract

We use a concerted theory-experiment effort to investigate the formation of chiral real space spin texture when the archetypal Dirac semimetal Cd$_3$As$_2$ is interfaced with In$_{1-x}$Mn$_x$As, a ferromagnetic semiconductor with perpendicular magnetic anisotropy. Our calculations reveal a nonzero off-diagonal spin susceptibility in the Cd$_3$As$_2$ layer due to the Rashba spin-orbit coupling from broken inversion symmetry. This implies the presence of a Dzyaloshinskii-Moriya interaction between local moments in the In$_{1-x}$Mn$_x$As layer, mediated by Dirac electrons in the vicinal Cd$_3$As$_2$ layer, potentially creating the conditions for a real space chiral spin texture. Using electrical magnetoresistance measurements at low temperature, we observe an emergent excess contribution to the transverse magneto-resistance 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.