(Ga,Mn)As is at the forefront of spintronics research exploring the synergy of ferromagnetism with the physics and the technology of semiconductors. However, the electronic structure of this model spintronics material has been debated and the systematic and reproducible control of the basic micromagnetic parameters and semiconducting doping trends has not been established. Here we show that seemingly small departures from the individually optimized synthesis protocols yield non-systematic doping trends, extrinsic charge and moment compensation, and inhomogeneities that conceal intrinsic properties of (Ga,Mn)As. On the other hand, we demonstrate reproducible, well controlled and microscopically understood semiconducting doping trends and micromagnetic parameters in our series of carefully optimized epilayers. Hand-in-hand with the optimization of the material synthesis, we have developed experimental capabilities based on the magneto-optical pump-and-probe method that allowed us to simultaneously determine the magnetic anisotropy, Gilbert damping and spin stiffness constants from one consistent set of measured data.

Faculty of Mathematics and Physics Charles University Prague Ke Karlovu 3 121 16 Prague 2 Czech Republic

See more in PubMed

Nat Mater. 2012 Feb 19;11(5):444-9 PubMed

Phys Rev Lett. 2008 Oct 10;101(15):157203 PubMed

Phys Rev Lett. 2008 Aug 15;101(7):077201 PubMed

Science. 1998 Aug 14;281(5379):951-5 PubMed

Nat Mater. 2012 Apr 23;11(5):360-1 PubMed

Phys Rev Lett. 2006 Aug 25;97(8):087208 PubMed

Phys Rev Lett. 2002 Jun 3;88(22):227201 PubMed

Nat Mater. 2010 Apr;9(4):299-303 PubMed

Phys Rev Lett. 2008 Feb 15;100(6):067202 PubMed

Phys Rev Lett. 2010 Nov 26;105(22):227202 PubMed

Phys Rev Lett. 2010 Nov 26;105(22):227201 PubMed

Phys Rev Lett. 2008 Jul 11;101(2):027202 PubMed

An antidamping spin-orbit torque originating from the Berry curvature