Observation of valence-band Landau-level mixing by resonant magnetotunneling

In magnetotunneling I(V,${\mathit{B}}_{\mathrm{\parallel }}$) measurements on strained p-type Si/${\mathrm{Si}}_{1\mathrm{-}\mathit{x}}$ ${\mathrm{Ge}}_{\mathit{x}}$ double-barrier resonant tunneling structures we observe heavy-hole satellite peaks that correspond to tunneling with Δn=1 and 2 changes in the Landau index n. The relative intensity of the satellite peaks excludes scattering as a possible mechanism. We ascribe the Δn=1,2 satellites to elastic tunneling made possible by Landau-level mixing in the valence band predicted by the Luttinger Hamiltonian in a magnetic field. The satellite peak spacing yields the valence-band Landau-level structure in strained ${\mathrm{Si}}_{1\mathrm{-}\mathit{x}}$ ${\mathrm{Ge}}_{\mathit{x}}$ quantum wells.