Orbital ordering transition in the single-layer manganites near half doping: a weak-coupling approach

作者：Sing Dheeraj Kumar^*

来源：European Physical Journal B, 2015, 88(4): 101.

DOI：10.1140/epjb/e2015-60044-3

The roles of crystal-field splitting and Jahn-Teller distortions on the orbital ordering transition are investigated in the single-layer manganites near half doping. Crystal-field splitting of energy levels favoring the d(3z2-r2) occupancy provides not only the correct Fermi surface topology for La0.5Sr1.5MnO4 having a circular electron pocket around the G point, but also enhances the flatness of the hole pocket around the M point thereby improving the nesting. In the presence of the circular electron pocket, Jahn-Teller distortions are found to be crucial for the transition to the transverse orbital ordering with ordering wavevector (0.5 pi, 0.5 pi). In the hole-doping regime 0.5 <= x <= 0.7, the orbital ordering wavevector shows a linear dependence on the hole concentration in accordance with the experiments.

• 出版日期2015-4-15