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, _chiral = (+) - (-), occurs in Weyl semimetals due to the charge imbalance of the CFs, monitoring spatial flow and temporal dynamics of _chiral has not been demonstrated yet. Here, we report real-space imaging and control of _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 _chiral. In THz electric and external magnetic fields, we visualize a spatial flow of coherent _chiral in macroscopic length scale and monitor its temporal dynamics in picosecond time scale, revealing its ultralong transport length around 100 micrometers. Such coherent _chiral is further found to be controlled according to field directions, suggesting the feasibility of information science with topological Dirac semimetals at RT.