  After growing successfully TaP single crystal, we measured its longitudinal
resistivity (rhoxx) and Hall resistivity (rhoyx) at magnetic fields up to 9T in
the temperature range of 2-300K. It was found that at 2K its magnetoresistivity
(MR) reaches to 328000 percent, at 300K to 176 percent at 8T, and both do not
appear saturation. We confirmed that TaP is indeed a low carrier concentration,
hole-electron compensated semimetal, with a high mobility of hole muh=371000
cm2V-1s-1, and found that a magnetic-field-induced metal-insulator transition
occurs at room temperature. Remarkably, as a magnetic field (H) is applied in
parallel to the electric field (E), the negative MR due to chiral anomaly is
observed, and reaches to -3000 percent at 9T without any signature of
saturation, too, which distinguishes with other Weyl semimetals (WSMs). The
analysis on the Shubnikov-de Haas (SdH) oscillations superimposing on the MR
reveals that a nontrivial Berry phase with strong offset of 0.3958 realizes in
TaP, which is the characteristic feature of the charge carriers enclosing a
Weyl nodes. These results indicate that TaP is a promising candidate not only
for revealing fundamental physics of the WSM state but also for some novel
applications.
