Magnetotransport in two-dimensional n-InGaAs∕GaAs double-quantum-well structures near the transition from the insulator to the quantum Hall effect regime

Abstract

The effective g-factor in In0.53Ga0.47As/In0.52Al0.48As quantum well investigated by magnetotransport measurement J. Appl. Phys. 113, 033704 (2013); 10.1063/1.4776236Electron dephasing scattering rate in two-dimensional GaAs/InGaAs heterostructures with embedded InAs quantum dotsThe temperature and magnetic-field dependence of the components of the conductivity and resistivity tensors are calculated with the quantum corrections due to the weak localization effect and electron-electron interaction taken into account in the diffusion and ballistic regimes. The corrections to the conductivity from the weak localization and electron-electron interaction and also the influence of spin and oscillation effects are taken into account by a renormalization of the transport relaxation time of the electron momentum, with the result that the Drude conductivity becomes temperature dependent. A calculation of the components of the conductivity and resistivity tensors is carried out with the use of the theoretical values of the parameters of the theory of quantum corrections, which are determined solely by the values of the carrier density and mobility of a particular sample. The results of the calculation are compared with experimental results for two-dimensional n-InGaAs/ GaAs structures with double quantum wells. It is shown that taking only the quantum corrections into account with the theoretical values of the parameters does not permit even a qualitative description of experiment, and it is therefore necessary to take additional temperature-dependent contributions to the Drude conductivity into account.

Interaction correction to conductivity of AlxGa1−xAs/GaAs double quantum well heterostructures near the balance

“…The correction to the conductivity due to e-e interaction 14 is investigated in DQW structures significantly less, 12,15 although it is of paramount importance in complicated systems. For instance, the effect of interaction on the conductivity has recently attracted a great deal of interest in a context of twodimensional (2D) systems with strong e-e interaction showing a metallic-type behavior of the conductivity, dσ/dT < 0.…”

Temperature dependence of quantum lifetime in n-InGaAs/GaAs structures with strongly coupled double quantum wells

“…q2 . Based on the analysis of DQW in transverse magnetic field at temperatures below 8 K, Hall effect in weak (R H (B,T)) and strong magnetic fields, as well as positive magnetoresistance in transverse magnetic field 17 at T ! 20 K, we determined the concentrations, mobilities and transport relaxation times of charge carriers in the subbands of S and AS states (n S,AS (T), l S,AS (T), s 1 tr ðTÞ, s 2 tr ðTÞ) and the Fermi energies 17).…”

“…Several theoretical 9-13 and experimental [15][16][17][18] studies have been devoted to solving this problem for structures with DQW (only Ref. 15 has considered strongly coupled DQW).…”

“…The presence of additional degrees of freedom in the quasi-2D systems containing two DQW coupled via tunneling leads to the whole range of new interesting magneto-transport phenomena, [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20] which are currently intensively studied using various kinetic methods. In particular, in zero magnetic field and under condition of equal charge carrier concentration in the wells (balance) and asymmetric scattering (charge-carrier mobilities differ in different wells), resonant resistance is observed.…”

“…Several possible reasons for that are currently discussed in literature. [8][9][10][11][12][13][14][15][16][17][18][19] In particular, the quasi-2D systems used in experiments are not yet sufficiently "ideal": the parameters of real structures do not satisfy the conditions built into various approximations within the frame of Fermi-liquid theory. For example, the concentrations of charge carriers in the structures currently used in electronics as well as in experiments are rather low.…”