Evidence of possible quantum orbital transfer and step-like transport jump in phase-separated manganites

Magnetic field induced step-like transport jump is found at low temperature for Pr doped phase-separated manganites. Magnetization measurements indicate that spin-stiffness constant D exhibits large magnetic field dependence. Moreover, there exists a remarkable change of spin-stiffness constant corresponding to the variety of the step-like transport jump. This suggests a possible existence of quantum orbital transfer resulting from the change of orbital ordering (OO) modes and accompanying with spin reorientation and carrier delocalization. The carrier delocalization is closely related to the coupling of charge–orbital and can be proved from the low temperature resistivity minimum behavior. The phase diagram was determined. These all show the importance of the strong interaction of charge–orbital and/or spin–orbital in the adjacent long-range charge-ordered antiferromagnetic phase, which depends sensitively on the OO modes.