Second Harmonic Generation in Spin-Glass Microstructures and Fabrication of Microstructures in IV-VI Epilayers

We studied magnetoconductance of two different mesoscopic systems: microregions containing two-dimensional electron gas adjacent to a grain-boundary plane in bicrystals of Hg$\text{}_{0.79}$Cd$\text{}_{0.19}$Mn$\text{}_{0.02}$Te and photolithographically patterned microstructures of Pb$\text{}_{1-x}$Mn$\text{}_{x}$Se. In both systems universal conductance fluctuations and generation of the second-harmonic voltage were observed at T ≤ 1 K. Moreover, in the former system the second harmonic signal exhibited distinct rise when the sample was cooled below the spin-glass freezing temperature (100 mK).