Unusual doping and temperature dependence of photoemission spectra from manganites

Prabuddha Sanyal, Subhra Sen Gupta, Nandan Pakhira, H. R. Krishnamurthy, D. D. Sarma, T. V. Ramakrishnan

Published 2007-04-30Version 1

A recent, major, puzzle in the core-level photoemission spectra of doped manganites is the observation of a 1-2 eV wide shoulder with intensity varying with temperature T as the square of the magnetization over a T scale of order 200K, an order of magnitude less than electronic energies. This is addressed and resolved here, by extending a recently proposed two electron fluid l-b model for these systems to include core-hole effects. The shoulder arises from a rapid redistribution of e_g electron density, as a function of T, between the highly localized (l) and band-like (b) states. Furthermore, our theory leads to a correspondence between spectral changes due to increasing doping and decreasing T, as experimentally observed.