Lateral hopping conductivity and large negative magnetoresistance in InAs/AlGaAs self-organized quantum dots

Abstract

We report experimental studies on lateral transport in self-organized quantum dots. We find that below 100 K, conduction occurs through interdot hopping and that experimental results are described quite well by a variable-range hopping model. In the hopping regime, the in-plane conductance varies as G = G 0 exp[(−T 0 /T ) 1/3 ], and T 0 is found to be 7100-9400 K. We have also observed a large negative magnetoresistance in this structure.

Spin relaxation in silicon coupled quantum dots

“…In materials where hopping is the mechanism responsible for conductivity, positive ͑negative͒ magnetoconductivity ͑magnetoresistance͒ characteristic has often been observed. 19 The positive magnetoconductivity has been reported in Si QDs structures. 18 Moreover, besides it, the magnetoconductivity at low magnetic fields ͑Ͻ1 T͒ exhibits much more information related to quantum interference in Si QDs structure.…”

Magnetoresistance effect in anion-substituted manganese chalcogenides

“…Magnetoresistance in semiconductors, the conductivity of which is described in the model with variable‐range hopping, has an exponential dependence where B is a parameter, H is the external magnetic field, is the radius of the electron localization . Experimental data on the magnetoresistance are satisfactorily described in the framework of this model with field H = 0.8 T and parameter B = 0.13 T −1 for T > T N , and B = 0.05 T −1 in the magnetically ordered region.…”

“…where B is a parameter, H is the external magnetic field, j ¼ 1=j1 À T=T N j is the radius of the electron localization [31][32][33][34]. Experimental data on the magnetoresistance are satisfactorily described in the framework of this model with field H ¼ 0.8 T and parameter B ¼ 0.13 T À1 for T > T N , and B ¼ 0.05 T À1 in the magnetically ordered region.…”

Characteristics of a high speed 1.22 μm tunnel injection p-doped quantum dot excited state laser

“…The characteristics are similar to those observed by Stevens et al 6 Interdot coupling in the same dot layer, which will cause level splitting in the same dot layer, is more efficient among the QD excited states. 22 Together, with the inhomogeneous broadening due to size fluctuation and the twofold degeneracy, there will be an efficient dynamic redistribution of carriers among dots with increasing injection. This can effectively broaden the width of the resonance and can also reduce gain compression effects.…”