Weak localization in thin Cs films

Thin, quench condensed films of Cs change their resistance and Hall effect dramatically when covered with surface impurities. In this paper we investi gate the quantum interference corrections to the resistance (weak localizat ion) and determine the inelastic dephasing rate of the conduction electrons . The dephasing rate is proportional to the temperature-dependent resistanc e. For pure Cs films the magnetoresistance curves show a rather poor agreem ent with the theory, which is exceptional for quench condensed metal films. In particular, at 4.5 K a linear magnetoresistance is observed at large ma gnetic fields, which defies explanation. Sandwiches of AgCs yield a much be tter agreement between the experimental results and the theory. However, th e dephasing rate of Cs in Ag/Cs and Au/Cs sandwiches has only half the valu e of that in pure Cs films with the same thickness and mean free path, [S01 63-1829(99)04611-1].