Emergence of fermionic finite-temperature critical point in a Kondo lattice

TL;DR

This paper demonstrates that in a Kondo lattice, a finite-temperature topological transition occurs where Dirac points emerge, leading to a Dirac semimetal state with distinctive thermal and magnetic responses.

Contribution

It reveals a novel finite-temperature critical point in a Kondo lattice driven by spin-orbit interactions, showing a transition from a strong to weak topological insulator with emergent Dirac semimetal behavior.

Findings

Finite-temperature topological transition at T_D

Emergence of Dirac semimetal with massless Dirac points

Critical scaling in thermal and magnetic responses near T_D

Abstract

The underlying Dirac point is central to the profound physics manifested in a wide class of materials. However, it is often difficult to drive a system with Dirac points across the massless fermionic critical point. Here by exploiting screening of local moments under spin-orbit interactions in a Kondo lattice, we show that below the Kondo temperature, the Kondo lattice undergoes a topological transition from a strong topological insulator to a weak topological insulator at a finite temperature $T_D$. At $T_D$, massless Dirac points emerge and the Kondo lattice becomes a Dirac semimetal. Our analysis indicates that the emergent relativistic symmetry dictates non-trivial thermal responses over large parameter and temperature regimes. In particular, it yields critical scaling behaviors both in magnetic and transport responses near $T_D$.