Detecting Topological Quantum Phase Transitions via the c-Function

Understand

We propose the c-function as a new and accurate probe to detect the location of topological quantum critical points.

• As a direct application, we consider a holographic model which exhibits a topological quantum phase transition between a topologically trivial insulating phase and a gapless Weyl semimetal.
• The quantum critical point displays a strong Lifshitz-like anisotropy in the spatial directions and the quantum phase transition does not follow the standard Landau paradigm.
• The c-function robustly shows a global feature at the quantum criticality and distinguishes with great accuracy the two separate zero temperature phases.