Lateral confinement effects on the Landau level dispersion in In 0.53Ga0.47As/InP quantum wires

The photoluminescence (PL) properties of undoped InGaAs/InP quantum wires are studied in a magnetic field up to 16 T. The quantum wires are fabricated with a combination of electron-beam lithography, reverse mesa wet etching, and metal organic-vapor-phase epitaxy overgrowth. Here we report results on wires with a vertical width of 50 Å and lateral widths from 450 Å to 250 Å. The purpose of this work is to study lateral confinement effects on the Landau level dispersion and many-body interactions in a one-dimensional semiconductor. A high carrier density is achieved by high intensity cw photo-excitation that is filling both conduction and valence band states. In this way it is possible to observe several Landau levels originating from the lowest ground state transition directly from the PL measurements. A pronounced effect of the lateral barriers is the quenching of classical Landau-orbits with cyclotron-diameter wider than the wire width. By varying the pump intensity at 14 T we observe some intriguing wire width dependent many-body effects