Electron effective mass and Si-donor binding energy in Ga As 1 − x N x probed by a high magnetic field

We study the magnetoresistance of the dilute nitride alloy $\mathrm{Ga}{\mathrm{As}}_{1\ensuremath{-}x}{\mathrm{N}}_{x}$ in magnetic fields up to $47\phantom{\rule{0.3em}{0ex}}\mathrm{T}$. We observe a strong magnetophonon resonance effect and a large transverse magnetoresistance, which provide the means of measuring the N-induced enhancement of the electron effective mass and of investigating the magnetic freeze-out of conduction electrons on Si donors in $\mathrm{Ga}{\mathrm{As}}_{1\ensuremath{-}x}{\mathrm{N}}_{x}$.