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 TD. At TD, 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 TD.
@article{arxiv.1604.03737,
title = {Emergence of fermionic finite-temperature critical point in a Kondo lattice},
author = {Po-Hao Chou and Liang-Jun Zhai and Chung-Hou Chung and Chung-Yu Mou and Ting-Kuo Lee},
journal= {arXiv preprint arXiv:1604.03737},
year = {2016}
}