Real-space imaging and control of chiral anomaly induced current at room temperature in topological Dirac semimetal.

Chiral fermions (CFs) in condensed matters, distinguished by right (+) or left (-) handedness, hold a promise for emergent quantum devices. Although a chiral anomaly induced current, J chiral = J (+) - J (-), occurs in Weyl semimetals due to the charge imbalance of the CFs, monitoring spatial flow and temporal dynamics of J chiral has not been demonstrated yet. Here, we report real-space imaging and control of J chiral on the topological Dirac semimetal KZnBi at room temperature (RT) by near-field terahertz (THz) spectroscopy, establishing a relation for an electromagnetic control of J chiral . In THz electric and external magnetic fields, we visualize a spatial flow of coherent J chiral in macroscopic length scale and monitor its temporal dynamics in picosecond time scale, revealing its ultralong transport length around 100 micrometers. Such coherent J chiral is further found to be controlled according to field directions, suggesting the feasibility of information science with topological Dirac semimetals at RT.