Journal Article

Extremely slow Drude relaxation of correlated electrons

Scheffler, Marc, Dressel, Martin, Jourdan, Martin, Adrian, Hermann

2005

Overview

The electrical conduction of metals is governed by how freely mobile electrons can move throughout the material. This movement is hampered by scattering with other electrons, as well as with impurities or thermal excitations (phonons). Experimentally, the scattering processes of single electrons are not observed, but rather the overall response of all mobile charge carriers within a sample. The ensemble dynamics can be described by the relaxation rates, which express how fast the system approaches equilibrium after an external perturbation 1 , 2 , 3 . Here we measure the frequency-dependent microwave conductivity of the heavy-fermion metal UPd 2 Al 3 (ref. 4 ), finding that it is accurately described by the prediction for a single relaxation rate (the so-called Drude response 5 ). This is notable, as UPd 2 Al 3 has strong interactions among the electrons 4 that might be expected to lead to more complex behaviour. Furthermore, the relaxation rate of just a few gigahertz is extremely low—this is several orders of magnitude below those of conventional metals (which are typically around 10 THz), and at least one order of magnitude lower than previous estimates for comparable metals. These observations are directly related to the high effective mass of the charge carriers in this material and reveal the dynamics of interacting electrons.

• Publisher: Nature Publishing Group UK,Nature Publishing,Nature Publishing Group
• Subject: Condensed matter: electronic structure, electrical, magnetic, and optical properties / Conductivity / Electronic conduction in metals and alloys / Electronic transport in condensed matter / Electrons / Exact sciences and technology / Heavy metals / Humanities and Social Sciences / letter / Metals / multidisciplinary / Particle physics / Physics / Scattering mechanisms and kondo effect / Science / Science (multidisciplinary)