Theory of the unusual doping and temperature dependence of photoemission spectra in manganites
| Autor: | Prabuddha Sanyal, H. R. Krishnamurthy, Nandan Pakhira, D. D. Sarma, T. V. Ramakrishnan, Subhra Sen Gupta |
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| Rok vydání: | 2008 |
| Předmět: | |
| Zdroj: | EPL (Europhysics Letters). 82:47010 |
| ISSN: | 1286-4854 0295-5075 |
| DOI: | 10.1209/0295-5075/82/47010 |
| Popis: | 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 200 K, an order of magnitude less than electronic energies. This is addressed and resolved here, by extending a recently proposed two-fluid polaron–mobile electron model for these systems to include core-hole effects. The position of the shoulder is found to be determined by Coulomb and Jahn-Teller energies, while its spectral weight is determined by the mobile electron energetics which is strongly T and doping dependent, due to annealed disorder scattering from the polarons and the t2g core spins. Our theory accounts quantitatively for the observed T dependence of the difference spectra, and furthermore, explains the observed correspondence between spectral changes due to increasing doping and decreasing T. |
| Databáze: | OpenAIRE |
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