Direct-current voltages in (Ga,Mn)As structures induced by ferromagnetic resonance

Abstract

Spin pumping is the phenomenon that magnetization precession in a ferromagnetic layer under ferromagnetic resonance produces a pure spin current in an adjacent non-magnetic layer. The pure spin current is converted to a charge current by the spin-orbit interaction, and produces a d.c. voltage in the non-magnetic layer, which is called the inverse spin Hall effect. The combination of spin pumping and inverse spin Hall effect has been utilized to determine the spin Hall angle of the non-magnetic layer in various ferromagnetic/non-magnetic systems. Magnetization dynamics of ferromagnetic resonance also produces d.c. voltage in the ferromagnetic layer through galvanomagnetic effects. Here we show a method to separate voltages of different origins using (Ga,Mn)As/p-GaAs as a model system, where sizable galvanomagnetic effects are present. Neglecting the galvanomagnetic effects can lead to an overestimate of the spin Hall angle by factor of 8, indicating that separating the d.c. voltages of different origins is critical.

Complementary spin-Hall and inverse spin-galvanic effect torques in a ferromagnet/semiconductor bilayer

“…Equation (2) yields values of y SH ¼ 1.7±0.9% (bolometric calibration) and 4% (Q-factor calibration), similar to spin-Hall angles previously reported for carriers with a p-orbital character in GaAs 36,37 . This agreement with previously measured spin-Hall angles is further evidence that the antidamping-like torque does not have a significant Rashba-symmetry SOT contribution.…”

Vector spectroscopy for spin pumping

“…In recent years, significant amount of research has been done in order to devise a universal method for separating ISHE from galvanomagnetic effects in spin pumping experiments. [12][13][14][17][18][19][20][21] The situation is complicated by the fact that the magnetic field spectrum of a voltage signal induced by AMR or AHE can have both symmetric (Lorentzian) and anti-symmetric (dispersive) contributions, and can fully overlap with the Lorentzian spectrum of the ISHE signal. [12][13][14] In this work, we propose a method to separate ISHE from galvanomagnetic effects by investigating the angular dependence of the symmetric and anti-symmetric parts of two orthogonal components of the induced dc electromotive force at FMR in a microwave cavity while changing the direction of the magnetic field out of the film plane.…”

“…That component of AMR which is perpendicular to J is often referred to as the planar Hall effect. 11 In case of spin pumping setups, 3,[12][13][14] both the electric field component and the magnetic field component of the microwave can induce an rf current in the sample. Coupling of the oscillating induction current j and of the dynamic magnetization m at FMR excited in thin sheets of ferromagnetic conductors by a microwave gives rise to time-independent electromotive forces (the spin rectification effect).…”

Room Temperature Uniaxial Magnetic Anisotropy Induced By Fe‐Islands in the InSe Semiconductor Van Der Waals Crystal

“…Thus, this hybrid system, which consists of Fe‐inclusions and a van der Waals crystal, enables the coexistence of magnetic and semiconducting properties within the same structure. Our findings will stimulate further research on magnetism in novel semiconductor materials beyond conventional Si27 and GaAs 28. Since vdW crystals are compatible with other vdW crystals, magnetic metals, and dielectrics, we envisage further developments and a new class of devices that exploit the magnetic properties of hybrid magnetic‐semiconducting materials.…”