IR Pump-probe Study of Phase Separated Hole-doped Manganite, La{sub}(1/4)Pr{sub}(3/8)Ca{sub}(3/8)MnO{sub}3

摘要

Ultrafast IR pump-probe spectroscopy is used to investigate La{sub}(1/4)Pr{sub}(3/8)Ca{sub}(3/8)MnO{sub}3 (LPCMO). Two types of coherent phonons strongly coupled with charge-ordering (CO) phase are observed. Temperature dependences of coherent phonons are explained by a hypothesis related with CO gap opening. According to the hypothesis, photo-induced electrons relax to acoustic phonon in the paramagnetic phase, but to optical phonons in the CO phase.