Topological Phase Transition and Chiral-Anomaly Driven Negative   Magneto-Resistance in Bulk Black Phosphorus
  We report the anisotropic magneto-transport measurement on a non-compound band semiconductor black phosphorus (BP) with magnetic field B up to 16 Tesla applied in both perpendicular and parallel to electric current I under hydrostatic pressures. The BP undergoes a topological Lifshitz transition from band semiconductor to a zero-gap Dirac semimetal state, characterized by a weak localization-weak antilocaliation transition at low magnetic fields and the emergence of a nontrivial Berry Phase of detected by SdH magneto-oscillations in magnetoresistance curves. In the transition region, we observe a pressure-dependent negative MR only in the B//I configuration. This negative longitudinal MR is attributed to the Adler-Bell-Jackiw anomaly (topological E$\cdot$B term) in the presence of weak antilocalization corrections. 
Chun-Hong Li, Yu-Jia Long, Ling-Xiao Zhao, Lei Shan, Zhi-An Ren,   Jian-Zhou Zhao, Hong-Ming Weng, Xi Dai, Zhong Fang, Gen-F...
cond-mat.mtrl-sci