Ground-state in-plane light-holes in GaAs/AlGaAs structures

We have performed low-temperature magnetoluminescence, far-infrared cyclotron resonance, and magneto-transport measurements on narrow (4.5 nm) GaAs/Al_0.25Ga_0.75 As single quantum-wells. The ground-state in-plane valence band was found to be light and nonparabolic, i.e., at zone center, the valence band mass is m_v ≈ 0. 1m₀ and for Fermi energies E_f ≈ 10 meV, m_v ≈ 0.25m₀.