Of Decoherent Electrons and Disordered Conductors

Abstract

Abstract:Electron decoherence at low temperatures is important for the proper understanding of the metallic ground state, usually studied within the framework of Fermi liquid theory. It is also fundamental to various insulating transitions in low-dimensional disordered conductors, such as Anderson localization, which similar to the Fermi liquid theory relies on a vanishing decoherence rate at zero temperature. I review a series of interference experiments designed to study decoherence by a variety of intrinsic and extrinsic mechanisms. The goal is to determine if there is a truly intrinsicand, in a sense, unavoidable-source of decoherence, coming from electronelectron interaction. In recent experiments we find that the saturation is not due to any mechanism involving magnetic impurities*. The interference experiments do indicate that there is an ultimate source of decoherence even at zero temperature.

Dynamical disappearance of superposition states in the thermodynamic limit

“…These same experiments seems to prove that this mechanism is intrinsic to the device. So, it has become desirable to understand a way to describe decoherence at zero temperature [3].…”