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.