Periodic Array Of Quantum Dots Research Articles

Structural Characterization of Reactive Ion Etched Semiconductor Nanostructures Using X-Ray Reciprocal Space Mapping

AbstractWe have studied GaAs/AlAs periodic quantum dot arrays using high resolution x-ray diffraction (reciprocal space mapping) around the (004) and (113) reciprocal lattice points. From the distribution of the diffracted intensities we deduced the average strain status of the dots. From the numerical simulations it is evident that random elastic strain fields are present, which extend through almost the entire volume of the quantum dot. The simulations of the x-ray measurements revealed that the crystalline part of the dots is considerably smaller as scanning electron micrographs would indicate.

The spectrum of a magneto-Bloch electron in a periodic array of quantum dots: Explicitly solvable model

The model of a periodic array of quantum dots in a magnetic field is constructed. The explicit form of the dispersion equation is obtained. The band structure of the spectrum of the magneto-Bloch electron in the array is described on the assumption that the magnetic flux is a rational one.

Theory of the Hall effect in two-dimensional quantum-dot arrays.

We investigate the problem of lateral ballistic quantum transport in two-dimensional periodic arrays of quantum dots in a transverse magnetic field. We argue that the B\"uttiker equations, applied to an array of quantum dots attached to ideal reservoirs, produce a Hall conductance which may be either positive or negative, and quantized in integer or fractional multiples of ${\mathit{e}}^{2}$/h. The fractions differ in value and in origin from the usual fractional quantum Hall effect. The physical reason for the complexity of this transport problem is that a quantum-dot array is capable of supporting edge currents which rotate either in a normal (right-hand) sense in a magnetic field, or in the opposite direction, or which are superpositions of different numbers of independent normal and counter-rotating states. The edge-state spectrum is therefore very rich, and a rich and interesting variety of transport phenomena is demonstrated. The effect of disorder on the transport problem (nonballistic transport) is briefly discussed.