Metallic State in Cubic FeGe Beyond Its Quantum Phase Transition

Abstract

We report on results of electrical resistivity and structural investigations on the cubic modification of FeGe under high pressure. The long-wavelength helical order (TC=280 K) is suppressed at a critical pressure pc≈19 GPa. An anomaly at TX(p) and strong deviations from a Fermi-liquid behavior in a wide pressure range above pc suggest that the suppression of TC disagrees with the standard notion of a quantum critical phase transition. The metallic ground state persisting at high pressure can be described by band-structure calculations if zero-point motion is included. The shortest FeGe interatomic distance display discontinuous changes in the pressure dependence close to the TC(p) phase line.