:::
:::

Prof. Chung-Yu Mou, Prof. Chung-Hou Chung (TG8) and collaborators published their research in Phys. Rev. Lett. on theoretical realization of fermionic finite-temperature Dirac points as critical points separating two topological phases in a Kondo lattice.

Research Highlight
Poster:Daw-Wei WangPost date:2016-05-02
Decorative image
Prof. Chung-Yu Mou, Prof. Chung-Hou Chung (TG8) and collaborators published their research in Phys. Rev. Lett. on April 29, 2016 on theoretical realization of fermionic finite-temperature Dirac points as critical points separating two topological phases in a Kondo lattice. 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, they show that below the Kondo temperature, the Kondo lattice undergoes a topological transition from a strong topological insulator (STI) to a weak topological insulator (WTI) at a finite temperature TD. At TD, massless Dirac points emerge and the Kondo lattice becomes a Dirac semimetal. Their 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. The finding in this paper is relevant for the recently heavily studied topological Kondo insulator SmB6. It also opens a new pathway to access the Dirac semimetallic phase and explore the fermionic critical point in the same system.

Prof. Mou and Chung are Coordinators of Thematic Group 8: Topology and Strong Correlations in Quantum Many-Body Systems

Figure: (a)Emergence of a finite-temperature Dirac point at Xpoint. (b) Phase diagram of the Kondo lattice model. Finite-temperature Dirac points TD(red curve) play a role as fermionic critical points, separating the STI from the WTI phases.The blue dashed lines indicate the crossover temperatureTthat separates the Dirac liquid regime from the Fermi liquidregime.

Reference:
Emergence of a fermionic finite-temperature critical point in a Kondo lattice, Po-Hao Chou , Liang-Jun Zhai, Chung-Hou Chung, Chung-Yu Mou, and Ting-Kuo Lee, Phys. Rev. Lett. 116, 177002 (2016).
 
Last modification time:2018-01-31 AM 8:51

cron web_use_log