Observations of Magnetoquantized Interface States by Electron Tunneling in Single-Barrier $n^{-}\left(\mathrm{InGa}\right)\mathrm{As}-\mathrm{InP}-n^{+}\left(\mathrm{InGa}\right)\mathrm{As}$ Heterostructures

A new type of tunneling phenomenon in forward-biased single-barrier $n^{+}\left(\mathrm{InGa}\right)\mathrm{As}-n^{-}\left(\mathrm{InGa}\right)\mathrm{As}-\mathrm{InP}-n^{+}\left(\mathrm{InGa}\right)\mathrm{As}$ heterostructures has been observed when a quantizing magnetic field is applied in the plane of the InP barrier. The occurrence of two distinct series of resonances in the voltage or field dependence of the current is interpreted in terms of electron tunneling from a 2D electron gas in the $n^{-}$ layer into interfacial Landau states in the $n^{+}\left(\mathrm{InGa}\right)\mathrm{As}$. These states correspond to classical skipping orbits of an electron along the tunnel-barrier interface.