Gap opening with ordering in PrFe4P12 studied by local tunneling spectroscopy

TL;DR

This study uses local tunneling spectroscopy to investigate the low-temperature ordered state of PrFe4P12, revealing a partial gap opening at 6.5 K associated with multipolar ordering.

Contribution

It provides direct spectroscopic evidence of a partial gap opening in PrFe4P12's ordered phase, linking electronic structure changes to multipolar ordering.

Findings

Anomalies in density of states at 6.5 K

Partial gap of about 2 meV observed

V-shaped density of states indicating gap opening

Abstract

We present measurements of the local tunneling density of states in the low temperature ordered state of PrFe4P12. The temperature dependencies of the Fermi level density of states and of the integrated density of states at low bias voltages show anomalies at T=6.5 K, the onset of multipolar ordering as detected by specific heat and other macroscopic measurements. In the ordered phase, we find a local density of states with a V-shape form, indicating a partial gap opening over the Fermi surface. The size of the gap according to the tunneling spectra is about 2 meV.