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arXiv · 2306.01167

Constraints on proximity-induced ferromagnetism in a Dirac semimetal (Cd$_3$As$_2$)/ferromagnetic semiconductor (Ga$_{1-x}$Mn$_x$Sb) heterostructure

Arpita Mitra·Run Xiao·Wilson Yanez·Yongxi Ou·Juan Chamorro·Tyrel McQueen·Alexander J. Grutter·Julie A. Borchers·Michael R. Fitzsimmons·Timothy R. Charlton·Nitin Samarth
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Abstract

Breaking time-reversal symmetry in a Dirac semimetal Cd$_3$As$_2$ through doping with magnetic ions or by the magnetic proximity effect is expected to cause a transition to other topological phases (such as a Weyl semimetal). To this end, we investigate the possibility of proximity-induced ferromagnetic ordering in epitaxial Dirac semimetal (Cd$_3$As$_2$)/ferromagnetic semiconductor (Ga$_{1-x}$Mn$_x$Sb) heterostructures grown by molecular beam epitaxy. We report the comprehensive characterization of these heterostructures using structural probes (atomic force microscopy, x-ray diffraction, scanning transmission electron microscopy), angle-resolved photoemission spectroscopy, electrical magneto-transport, magnetometry, and polarized neutron reflectometry. Measurements of the magnetoresistance and Hall effect in the temperature range 2 K - 20 K show signatures that could be consistent with either a proximity effect or spin-dependent scattering of charge carriers in the Cd$_3$As$_2$ channel. Polarized neutron reflectometry sets constraints on the interpretation of the magnetotransport studies by showing that (at least for temperatures above 6 K) any induced magnetization in the Cd$_3$As$_2$ itself must be relatively small ($<$ 14 emu/cm$^3$).

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Arpita Mitra, Run Xiao, Wilson Yanez, Yongxi Ou, Juan Chamorro, Tyrel McQueen, Alexander J. Grutter, Julie A. Borchers, Michael R. Fitzsimmons, Timothy R. Charlton, Nitin Samarth. 2023-06-01. Constraints on proximity-induced ferromagnetism in a Dirac semimetal (Cd$_3$As$_2$)/ferromagnetic semiconductor (Ga$_{1-x}$Mn$_x$Sb) heterostructure. https://doi.org/10.1103/physrevmaterials.7.094201

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