Physical Review B 64, 125324 (2001)

Bước tới: chuyển hướng, tìm kiếm
Effect of impurity correlation in modulation-doped quantum wires
Effect of impurity correlation in modulation-doped quantum wires
 Tạp chí Physical Review B 2001 11 November 2001; 64 (12):125324
 Tác giả   Doan Nhat Quanga, Nguyen Huyen Tung b and Tran Doan Huanb
 Nơi thực hiện   a Center for Theoretical Physics, National Center for Science and Technology, P.O. Box 429, Boho, Hanoi 10000, Vietnam

bInstitute of Engineering Physics, Hanoi University of Technology, 1 Dai Co Viet Road, Hanoi, Vietnam

 Từ khóa   impurity correlation, quantum wire, electron mobility


A theory is given of the electronic properties of modulation-doped quantum wires which undergo a thermal treatment, taking into account the Coulomb interaction among ionized impurities in the sample preparation. It is pointed out that the correlation among impurities weakens their field and is enhanced when elevating the doping level, lowering the freezing temperature for impurity diffusion, and reducing the size of the impurity system. The screening of the ionic correlation by charge carriers in the sample growth is of minor importance. In the limiting case of a one-dimensional impurity system, the correlation may totally suppress the random field at any doping level, so that a finite electron mobility is governed by other scattering mechanisms than impurity doping, e.g., interface roughness and alloying. It is found that the ionic correlation changes the electron mobility of quantum wires as regards not only its magnitude but its dependence on the doping conditions as well. For impurity systems of a small size, the mobility may be increased by up to more than one order of magnitude at a doping level of 10^{6}cm{-1}.