We report the occurrence of reentrant metallic behavior in the Weyl semimetal NbP. When the applied magnetic field H is above a critical value Hc, a reentrance appears as a peak in the temperature dependent resistivity ρxx(T) at T = Tp, similar to that observed in graphite where it was attributed to local superconductivity. The Tp(H) relationship follows a power-law dependence Tp ~(H − Hc)!/! where ν can be derived from the temperature dependence of the zero-field resistivity ρ0(T) ~ Tv. From concurrent measurements of the transverse ρxx(T) and Hall ρxy(T) magnetoresistivities, we reveal a clear correlation between the rapidly increasing ρxy(T) and the occurrence of a peak in the ρxx(T) curve. Quantitative analysis indicates that the reentrant metallic behavior arises from the competition of the magnetoconductivity σxx(T) with an additional component Δσxx(T) = κHσxx(T) where κH = [ρxy(T)/ρxx(T)]2 is the Hall factor. We find that the Hall factor (κH ≈ 0.4) at peak temperature Tp is nearly field-independent, leading to the observed Tp(H) relationship. Furthermore, the reentrant metallic behavior in ρxx(T) also is reflected in the behavior of ρxx(H) that ranges from non-saturating at T > 70 K to saturation at liquid helium temperatures. The latter can be explained with the magnetic field dependence of the Hall factor κH(H). Our studies demonstrate that a semiclassical theory can account for the ‘anomalies’ in the magnetotransport phenomena of NbP without invoking an exotic mechanism.
|Original language||English (US)|
|State||Published - Sep 14 2017|
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