A delta-doped quantum well system with additional modulation doping
1 Department of Physics, National Tsinghwa University, Hsinchu, 300, Taiwan
2 Department of Electrophysics, National Chiayi University, Chiayi, 600, Taiwan
3 Department of Physics, National Taiwan University, Taipei, 106, Taiwan
4 Department of Electronics Engineering, National Chiao Tung University, Hsinchu, 300, Taiwan
5 National Measurement Laboratory, Centre for Measurement Standards, Industrial Technology Research Institute, Hsinchu, 300, Taiwan
Nanoscale Research Letters 2011, 6:139 doi:10.1186/1556-276X-6-139Published: 14 February 2011
A delta-doped quantum well with additional modulation doping may have potential applications. Utilizing such a hybrid system, it is possible to experimentally realize an extremely high two-dimensional electron gas (2DEG) density without suffering inter-electronic-subband scattering. In this article, the authors report on transport measurements on a delta-doped quantum well system with extra modulation doping. We have observed a 0-10 direct insulator-quantum Hall (I-QH) transition where the numbers 0 and 10 correspond to the insulator and Landau level filling factor ν = 10 QH state, respectively. In situ titled-magnetic field measurements reveal that the observed direct I-QH transition depends on the magnetic component perpendicular to the quantum well, and the electron system within this structure is 2D in nature. Furthermore, transport measurements on the 2DEG of this study show that carrier density, resistance and mobility are approximately temperature (T)-independent over a wide range of T. Such results could be an advantage for applications in T-insensitive devices.