Collapse of the charge ordering gap of Nd_{0.5}Sr_{0.5}MnO_{3} in an applied magnetic field

TL;DR

This study investigates how an applied magnetic field affects the charge ordering gap in Nd_{0.5}Sr_{0.5}MnO_{3}, revealing that the gap collapses under magnetic influence, correlating with resistivity changes.

Contribution

It demonstrates the magnetic field-induced collapse of the charge ordering gap in Nd_{0.5}Sr_{0.5}MnO_{3} and links this to the melting of the charge ordered state.

Findings

Charge ordering gap opens at 150K in zero field.

Magnetic field collapses the charge ordering gap.

Resistivity behavior correlates with gap collapse.

Abstract

We report results of tunneling studies on the charge ordering compound Nd_{0.5}Sr_{0.5}MnO_{3} in a magnetic field up to 6T and for temperature down to 25K.We show that a gap (2\Delta_{CO} \approx 0.5eV opens up in the density of state (DOS) at the Fermilevel (E_F) on charge ordering (T_{CO}=150K) which collapses in an applied magnetic field when the charge ordered state melts. There is a clear correspondence between the behavior of the resistivity and the gap formation and its collapse in an applied magnetic field. We conclude that a gap in the DOS at E_F is necessary for the stability of the charge ordered state.