PT Journal AU Gershenzon, EM Gol'tsman, GN Elant'ev, AI TI Energy spectrum of the donors in GaAs and Ge and its reaction to a magnetic field SO Sov. Phys. JETP JI Sov. Phys. JETP PY 1977 BP 555 EP 565 VL 45 IS 3 DE Ge; GaAs; magnetic field; donors; energy spectrum AB The spectrum of the submillimeter photoconductivity of n-GaAs and n-Ge in a magnetic field up to 60 kOe at helium temperatures was investigated. A large number of lines due to transitions between excited states of the donors have been investigated, and the measurement results were used to determine a number of levels of the energy spectrum in a wide range of magnetic fields. For GaAs, these data are compared with calculations of the energy spectrum of the hydrogen atom in magnetic fields up to -2X lo9 Oe. For the donors in Ge, the energy spectrum is investigated at different orientations of the magnetic field relative to the crystallographic axes (H 11 [loo], [I 1 I], [110]), and these results are also compared with the corresponding calculations. ER