Control of Magnetic Properties of (Ga,Mn)As and GaAs-Compatible Ferromagnetic Heterostructures*

Magnetic semiconductors and ferromagnet/semiconductor heterostructures are two promising material systems for manipulating the spin degree of freedom of charge carriers in semiconductors to merge functionalities of information storage, logic and communications into one chip. In this talk, I shall first present our recent work on robust modulation of magnetism in (Ga,Mn)As [1,2], a prototypical member of the family of magnetic semiconductors. We realized giant modulation of the magnetism, including complete demagnetization of ferromagnetism, in (Ga,Mn)As via electric field with the assistance of a special dielectric, ionic liquid or solid state ionic gel [3]. I shall then describe the MBE growth and characterizations of several ferromagnet/semiconductor heterostructures, featuring the GaAs-compatible Mn-based binary alloy films with large perpendicular magnetic anisotropy (PMA) [4,5]. I shall provide the three electrical transport features which support the presence of the orbital two-channel Kondo effect in epitaxial L1₀-MnAl film with PMA [6,7]. Finally, I shall show the observation of well-defined tunneling magnetic resistance of L1₀-MnGa based perpendicularly magnetic tunnel junctions [8].

References:
[1] X. L. Wang et al., Adv. Mater. 27 (2015) 8043.
[2] J. L. Ma et al., Europhysics Lett. 118 (2017) 17003.
[3] H. L. Wang et al., to be submitted.
[4] L. J. Zhu et al., Adv. Mater. 24 (2012) 4547.
[5] S. H. Nie et al., Appl. Phys. Lett. 102 (2013) 152405.
[6] L. J. Zhu et al., Nature Commun. 7 (2016) 10817.
[7] L. J. Zhu et al., Phys. Rev. B 93 (2016) 195112.
[8] S.W. Mao et al., Sci. Rep. 7 (2017) 43064.