Shubnikov–de Haas oscillations of two-dimensional electron gas in an InAsN/InGaAs single quantum well

We present the first investigation of Shubnikov–de Haas (SdH) oscillations of two-dimensional electron gas formed in an InAsN/InGaAs single quantum well (QW) grown on an InP substrate using gas source molecular beam epitaxy and a radio-frequency (rf) plasma nitrogen source. The photoluminescence (PL) peak energy of the InAsN/InGaAs QW decreases compared with that of InAs/InGaAs QW. This agrees with the bowing effect due to the incorporation of nitrogen atoms. The nitrogen content can be estimated to be 0.4% using the PL peak positions as well as x-ray diffraction. From the SdH oscillations, the carrier concentration is 2.85 × 1011 cm−2 and the effective mass is 0.1± 0.01m0. The enhancement of the effective mass is mainly due to the incorporation of the nitrogen atoms in the InAs lattice, which is consistent with a recent study on InAsN bulk alloys. The large increase of the effective mass cannot be explained by the simple band anticrossing model. In addition, we observe a temperatureindependent magnetoresistivity at a critical magnetic field. Our analysis supports the fact that the value of the critical exponent in the quantum Hall effect is not universal.