Charge counting statistics (C.S.) of traversing electron in quantum devices like atomic-molecular junctions is sensitive to the local perturbation in the charge field at the contact and in the... Show moreCharge counting statistics (C.S.) of traversing electron in quantum devices like atomic-molecular junctions is sensitive to the local perturbation in the charge field at the contact and in the quantum channels. The first cumulant of C.S. i.e. current-voltage characteristic of such devices has been tool for such investigation since long time. Here we have used the second cumulant i.e. shot noise to study the electron-electron and electron-phonon interaction in the atomic contacts. The shot noise measurement on the Au atomic chain reveals the inelastic scattering in the noise. These signatures can provide vital information on the feedback of the local phonon population on electron transport. The current-voltage characteristic of the ferromagnetic atomic contacts unexpectedly shows zero bias anomalies. This observation is attributed to the interaction of traversing electron with localized magnetic moments within same host species. The observed connection between the Fano factor and the weight of the zero bias anomalies supports the view that the zero bias anomaly originates from spin scattering by localized magnetic moments. However, whether this is true Kondo scattering as suggested by Calvo et al. cannot be stated conclusively from our data. At the end of thesis we have presented a low noise high frequency broadband noise measurement setup suitable for break junction setup. Show less
This thesis describes the formation and physical properties of atomic chains consisting of metal atoms and incorporated small molecules. Small molecules like oxygen and hydrogen modify the... Show moreThis thesis describes the formation and physical properties of atomic chains consisting of metal atoms and incorporated small molecules. Small molecules like oxygen and hydrogen modify the electrical and mechanical properties of these wires, resulting in new one-dimensional conductors. Show less