Key words In x Ga 1-x As/In y Al 1-y As QW, magneto-transport, Shubnikov-de Haas oscillations. PACS 73.40 HmThe magneto-transport measurements in InGaAs/InAlAs quantum wells (QW) obtained b y MOCVD technology on InP substrates, and known as High Electron Mobility Transistors, were performed at low temperatures of 0.4 -15 K and high magnetic fields up to 10 T (with the magnetic field induction B perpendicular to the plane of the well). Three kinds of structures were studied. The Shubnikov-de Haas oscillations demonstrating the occupancy of two subbands were observed. In order to determine the energies of Landau levels in the QW subbands, we have used the Zawadzki-Pfeffer quazi-two-band model. Good agreement between calculated Landau levels and Fermi level from one hand, and positions of the Shubnikovde Haas oscillations peaks from the other, enable us to determine the parameters of 2D electron gas in QW: effective mass and carrier density.

We carried out magneto‐transport measurements in InxGa1–xAs/InyAl1–yAs quantum wells (QW) obtained by MOCVD technology on InP substrates, and known as High Electron Mobility Transistors (HEMT). The galvanomagnetic measurements were performed at low temperatures of 1.65–15 K in high magnetic fields up to 10 T (with B perpendicular to the plane of the well). Shubnikov–de Haas oscillations as well as the Quantum‐Hall effect demonstrating the occupancy of two sub‐bands were observed.

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