The persistent photoconductivity effect in unintentionally doped n-GaN grown by metal organic chemical vapor deposition(MOCVD)is presented.

Optical quenching of persistent photoconductivity (PPC) in n-type unintentional doped GaN and Si-doped GaN is investigated.

The persistent current and the quantum energy spectrum in mesoscopic metal dual rings;

The persistent current in a mesoscopic Aharonov-Bohm ring with a series-coupled double quantum dot;

Influences of a magnetic field on the persistent currents of mesoscopic coupling metallic ring;

Based on quantum waveguide theory,the effect of impurities on the transmission probability and the persistent currents in mesoscopic structure is studied.

The persistent currents in one dimensional non metal mesoscopic ring are studied using Zou Andersons Slave Fermion method with large U Hubbard model at heavy doping condition.

The one-dimensional normal metal mesoscopic ring, which was affected by dis-order in an inhomogeneous field, is studied, The conclusion that of f-diagonal decreased the amplitude of persistent currents more than diagonal disorder is obtained.