title: Emergence of a Fermionic Finite-Temperature Critical Point in a Kondo Lattice.
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 nontrivial thermal responses over large parameter and temperature regimes. In particular, it yields critical scaling behaviors both in magnetic and transport responses near T_{D}.
authors.affiliation: Department of Physics, National Tsing Hua University, Hsinchu 30013, Taiwan, Republic of China.
authors.forename: Po-Hao
authors.initials: PH
authors.lastname: Chou
authors.affiliation: Department of Physics, National Tsing Hua University, Hsinchu 30013, Taiwan, Republic of China.
authors.forename: Liang-Jun
authors.initials: LJ
authors.lastname: Zhai
authors.affiliation: Electrophysics Department, National Chiao-Tung University, HsinChu 30010, Taiwan, Republic of China.
authors.forename: Chung-Hou
authors.initials: CH
authors.lastname: Chung
authors.affiliation: Department of Physics, National Tsing Hua University, Hsinchu 30013, Taiwan, Republic of China.|Institute of Physics, Academia Sinica, Nankang 115, Taiwan, Republic of China.|Physics Division, National Center for Theoretical Sciences, P.O.Box 2-131, Hsinchu 30013, Taiwan, Republic of China.
authors.forename: Chung-Yu
authors.initials: CY
authors.lastname: Mou
authors.affiliation: Institute of Physics, Academia Sinica, Nankang 115, Taiwan, Republic of China.
authors.forename: Ting-Kuo
authors.initials: TK
authors.lastname: Lee