Momentum-Dependent Hybridization Gap and dispersive in-gap state of The Kondo Semiconductor SmB6

TL;DR

This study uses temperature-dependent 3D angle-resolved photoemission spectroscopy to investigate the hybridization gap and in-gap states in the Kondo semiconductor SmB6, revealing distinct temperature-dependent behaviors at different momentum points.

Contribution

It provides new insights into the momentum-dependent hybridization and magnetic excitations in SmB6, highlighting differences at the X and Γ points.

Findings

Hybridization peaks at X and Γ points show different temperature dependencies.

Valence transition correlates with the X point peak intensity.

Magnetic excitation is linked to the Γ point initial state.

Abstract

We report the temperature-dependent three-dimensional angle-resolved photoemission spectra of the Kondo semiconductor SmB$_6$. We found a difference in the temperature dependence of the peaks at the X and $\Gamma$ points, due to hybridization between the Sm 5d conduction band and the nearly localized Sm 4f state. The peak intensity at the X point has the same temperature dependence as the valence transition below 120 K, while that at the $\Gamma$ point is consistent with the magnetic excitation at Q=(0.5,0.5,0.5) below 30 K. This suggests that the hybridization with the valence transition mainly occurs at the X point, and the initial state of the magnetic excitation is located at the $\Gamma$ point.