Novel photoinduced phase transitions in transition metal oxides and diluted magnetic semiconductors
Department of Complexity Science and Engineering, University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba, 277-8561, Japan
Nanoscale Research Letters 2012, 7:582 doi:10.1186/1556-276X-7-582Published: 23 October 2012
Some transition metal oxides have frustrated electronic states under multiphase competition due to strongly correlated d electrons with spin, charge, and orbital degrees of freedom and exhibit drastic responses to external stimuli such as optical excitation. Here, we present photoemission studies on Pr0.55(Ca1 − ySry)0.45MnO3 (y = 0.25), SrTiO3, and Ti1 − xCoxO2 (x = 0.05, 0.10) under laser illumination and discuss electronic structural changes induced by optical excitation in these strongly correlated oxides. We discuss the novel photoinduced phase transitions in these transition metal oxides and diluted magnetic semiconductors on the basis of polaronic pictures such as orbital, ferromagnetic, and ferroelectric polarons.