From unconventional insulating behavior towards conventional magnetism in the intermediate-valence compoundSmB6

Abstract

In intermediate valence compounds, the subtle quantum equilibrium of two microscopic configurations is at the origin of a very rich physics. ${\text{SmB}}_{6}$ is a famous example as it displays an intriguing semiconducting behavior at low pressure and a magnetic phase at high pressure. New transport measurements on ${\text{SmB}}_{6}$ under hydrostatic conditions show that the two phenomena are intimately linked. The insulating state vanishes just at the pressure $(p=10\text{ }\text{GPa})$ where homogeneous long range magnetic order appears. A comparison to previous specific heat experiments clearly points out that a magnetic anomaly is observed in resistivity measurements when excellent hydrostatic conditions are realized. The particular sensitivity of ${\text{SmB}}_{6}$ to pressure inhomogeneities may reflect the strong anisotropy in the band structure.