Coulomb related Landau spectra of axial and double acceptors in germanium

The absorption spectra of Landau features associated with Coulomb states of the axial single-hole acceptors ZnH and CuX and the double-hole acceptor, neutral zinc (Zn⁰), all in Ge, have been observed. The magnetic field B was oriented along 〈111〉 for ZnH and Zn⁰ and 〈100〉 for CuX. The main Landau features for these are the same as those of the group III acceptors in Ge. The differences are in the fine structure of the Landau lines. Under B, the ground state of B consists of four Zeeman levels, those of ZnH and CuX are doublets while that of Zn⁰ is singlet. Coulomb-related Landau state are the same for B, ZnH and CuX but not so for Zn⁰. The excited states of the latter are revealed to be compound two-hole states.