Compositional Evolution of Bi-induced acceptor states in GaAs_1-xBi_x alloy, G. Pettinari, H. Engelkamp, P. C. M. Christianen, J. C. Maan, A. Polimeni, M. Capizzi, X. Lu, T. Tiedje, Phys. Rev. B 83, 201201 (2011)

Far-infrared absorption measurements have been performed in nominally undoped GaAs_1-xBi_x (0.6%≤x≤10.6%) for magnetic field up to 30 T. For 0.6%≤x≤4.5%, the Lyman series of an acceptor has been observed. An exceedingly high value of the ground-state g factor provides strong evidence of Bi-related acceptor states. For x=5.6%, however, these acceptors suddenly disappear. Such anomalous dependence on Bi concentration parallels those recently reported in GaAs_1-xBi_x for other electronic and structural properties.