Correlations and Semimetallic Behaviors in Pyrochlore Oxide Cd2Re2O7

TL;DR

This paper investigates the electronic properties of Cd2Re2O7, revealing semimetallic behavior, significant changes at structural phase transitions, and strong electron correlations affecting its metallic state.

Contribution

It provides experimental evidence of semimetallic band structures and highlights the impact of structural transitions and correlations on electronic properties.

Findings

Semimetallic band structures confirmed by measurements

Large carrier density and mass changes at 200 K transition

Significant mass enhancement indicating strong correlations

Abstract

Electronic properties of the metallic pyrochlore oxide Cd2Re2O7 are studied by means of electrical resistivity and Hall measurements. Semimetallic band structures are revealed as expected from band structure calculations. It is found that large changes in carrier density and mass occur at the structural phase transition at Ts1 = 200 K. A large mass enhancement is observed, particularly for the high-temperature phase with the ideal pyrochlore structure, suggesting that an anomalous correlation has an important effect on the itinerant electrons in the pyrochlore lattice.