Enhancement of Curie temperature in Ga(1-x)Mn(x)As/Ga(1-y)Al(y)As ferromagnetic heterostructures by Be modulation doping

Abstract

The effect of modulation doping by Be on the ferromagnetic properties of Ga(1-x)Mn(x)As is investigated in Ga(1-x)Mn(x)As/Ga(1-y)Al(y)As heterojunctions and quantum wells. Introducing Be acceptors into the Ga(1-y)Al(y)As barriers leads to an increase of the Curie temperature T_C of Ga(1-x)Mn(x)As, from 70 K in undoped structures to over 100 K with the modulation doping. This increase is qualitatively consistent with a multi-band mean field theory simulation of carrier-mediated ferromagnetism. An important feature is that the increase of T_C occurs only in those structures where the modulation doping is introduced after the deposition of the magnetic layer, but not when the Be-doped layer is grown first. This behavior is expected from the strong sensitivity of Mn interstitial formation to the value of the Fermi energy during growth.

12 pages, 3 figures

References in corpus (5)

• Ferromagnetic semiconductors
• High Curie temperature GaMnAs obtained by resistance-monitored annealing
• High Ferromagnetic Transition Temperature (172K) in Mn delta-doped GaAs with p-type Selective Doping
• Spin interactions of interstitial Mn ions in ferromagnetic GaMnAs
• Fundamental Curie temperature limit in ferromagnetic GaMnAs

Cited by in corpus (13)

• Dilute ferromagnetic semiconductors: Physics and spintronic structures
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• Carrier-mediated antiferromagnetic interlayer exchange coupling in diluted magnetic semiconductor multilayers Ga${}_{1-x}$Mn${}_x$As/GaAs:Be
• Disorder-Induced Resistive Anomaly Near Ferromagnetic Phase Transitions
• Charge inhomogeneities and transport in semiconductor heterostructures with a manganese $\delta$-layer
• Definitive Evidence of Interlayer Coupling Between (Ga,Mn)As Layers Separated by a Nonmagnetic Spacer
• Improved-Sensitivity Integral SQUID Magnetometry of (Ga,Mn)N Thin Films in Proximity to Mg-doped GaN
• Structural and transport properties of GaAs/delta<Mn>/GaAs/InxGa1-xAs/GaAs quantum wells
• Nematicity of correlated systems driven by anisotropic chemical phase separation
• Theory of spin waves in diluted-magnetic-semiconductor quantum wells
• Noise studies of magnetization dynamics in dilute magnetic semiconductor heterostructures
• Static polarizability of two-dimensional hole gases
• Optimizing Tc in the (Mn,Cr,Ga)As and (Mn,Ga)(As,P) Ternary Alloys