Anomaly close to an electronic topological semimetal-insulator transition in elemental fcc-Yb under pressure.

The Lifshitz-type semimetal-insulator transition, which is a transition of the electronic topology, has been considered as the most fundamental metal-insulator transition. Here, we present resistivity measurements under pressure in the vicinity of the quantum critical point of fcc Yb. We apply a previously suggested scaling for this type of transition and identify its universality class. Moreover, we observe an anomaly in the screening coefficient A of the T2 term in the resistivity at low temperatures in the metallic phase. We suggest an interpretation of this phenomenon as an effect of doping by Ca impurities unintentionally present in the Yb crystals. The observed behavior may very well be applicable to any doped system in the vicinity of such a transition. [ABSTRACT FROM AUTHOR]