Broadband electrical detection of spin excitations in Ga0.98Mn0.02As using a photovoltage technique

Abstract

We report on microwave photovoltage and simultaneous magnetotransport measurements in a (Ga, Mn) As film oriented normal to the magnetic field. We detect the ferromagnetic resonance over a broad frequency range of 2–18.5GHz and determine the spectroscopic g-factor and separate the Gilbert from the inhomogeneous contribution to magnetization relaxation. Temperature dependent measurements below the saturation magnetization indicate that the photovoltage signal can serve as a sensitive tool to study the crystal anisotropy. We demonstrate that the combination of spin dynamics with charge transport is a promising tool to study microstructured ferromagnetic semiconductor samples.