This Condensed Matter Physics project investigates the magneto-resistance and normal electrical transport in what is generally considered the simplest examples of a nearly free electron system, the alkali metals, lithium, sodium, potassium, rubidium and cesium. However, recent experiments on thin alkali films show very unusual behavior, which can not be explained within the nearly free electron model. The research will investigate origins of this behavior in films with impurity coverages of 1/100th of a monolayer, where dramatic increases of resistances and negative Hall constants are observed. The anomalous magneto-resistance of films of potassium below 20 K will also be investigated. Low coverage of these films with lead also leads to behavior not readily understood with conventional theory of weak localization. Additional anomalies are also identified and targeted for study. The research is particularly well suited for graduate and undergraduate education in that it provides training if both fundamental and applied physics. %%% The alkali metals lithium, sodium, potassium, rubidium and cesium are generally considered as the simplest metals in the periodic table. However, a theory developed by A. W. Overhauser some 30 years ago predicts a very complex structure for the alkali metals. This Condensed Matter Physics project will investigate recent experiments in the principal investigator's laboratory that also point to anomalous properties for the alkali metals. The work focuses on thin films of the metals. The transport properties of these films, with and without a magnetic field display a range of behavior that does not agree with the conventional theory and may require a different treatment such as that proposed by Overhauser. It is interesting that the metals in the first row of the periodic table represent in many ways an unexplored territory. The research is very well suited to graduate and undergraduate education in that it provides training in both fundamental and applied physics. The students receive training in sophisticated experimental methods and also learn the even the "well known" first row elements have novel properties that challenge conventional understanding.
