1/fNOISE IN NANOMATERIALS AND NANOSTRUCTURES: OLD QUESTIONS IN A NEW FASHION

摘要

Some old, perennial questions in the field of low-frequency noise in solid are discussed in the light of some recent achievements concerning the investigation of the noise phenomena in nanomaterials and nanostructures. The main emphasis is placed on the very old yet still hot topic of 1/f noise. Possible new fashion is considered for three longstanding questions: Lorentzian superposition, surface vs. bulk and number vs. mobility fluctuation. Examination of the RTS noise behaviour in meso- and nanostructures does not support its fundamental character in the generation of the 1/f noise. Recent noise measurements on both Single- and Multiple-Walled Carbon Nanorubes (SWNT, MWNT) definitely relax the old dispute whether 1/f noise is a surface or a bulk effect: either surface or bulk or both of them can contribute to 1/f noise. As for the number fluctuation vs. mobility fluctuation controversy, noise measurements in nanomaterials favour mobility fluctuation hypothesis due to phonon scattering as the microscopic source of the 1/f noise.