Observations of Magnetoresistance Oscillations in aQuantum Dot Array System

摘要

We fabricate a quantum dot array system arranged with asimilar shape of Kagomé lattice, where the carriers of two-dimensionalelectron gas (2DEG) are electrostatically induced by a back gate voltageand both the confining potential of dots and the interaction strengthbetween dots are controlled by a surface gate voltage. Themagnetoresistance of quantum dot array systems is measured at T=30mK and magnetoresistance oscillations are observed at specific surfacegate voltages. From the Fourier spectrum analysis of oscillations, we findthat the periodicities of magnetoresistance oscillations correspond to theAharanov-Bohm oscillations of triangular lattices and hexagonal lattices.This implies the coherent transport of electrons through quantum dotslattices and it is necessary to realize the flat-band ferromagnetism. This isthe first step toward the realization of semiconductor ferromagnets.