Anomalous Shift of Chemical Potential in the Double-Exchange Systems

Double-exchange system is investigated by the dynamical mean-field theory. We show that the chemical potential shifts as a function of temperature and magnetization, which is anomalously large. We also discuss the influences of dynamic Jahn-Teller effect to the shift of the chemical potential. Measurement of the shift of the chemical potential casts a constraint to theoretical approaches for the magnetoresistance phenomena in ($R$,$A$)MnO$_3$ such as double-exchange effects and dynamic Jahn-Teller effects. We also propose a method to measure the shift of $\mu$.