A new way to see: real-space imaging of chiral fermion currents at room temperature

In the article “Real-space imaging and control of chiral anomaly induced current at room temperature in topological Dirac semimetal”, published in Science Advances, B. C. Park et al. from Sungkyunkwan University and collaborating partners report a world first: the spatio-temporal motion of chiral fermions resolved in a direct measurement.

Why chiral fermions matter

Chiral fermions are expected to play a key role in future quantum devices. Their spatio-temporal motion, however, had not been resolved in a direct measurement before.

Picoseconds and micrometres

Using a TeraCube M2 THz near-field scanning system, the team demonstrated real-space imaging — and also control — of chiral-anomaly-induced currents in the topological Dirac semimetal KZnBi at room temperature, on a picosecond time scale and a micrometre length scale.

The results bring topological Dirac semimetals a big step closer to use in information technology.

The work illustrates what time-resolved THz near-field imaging adds to quantum-materials research: the photoconductive microprobe records the full THz waveform at every pixel, so dynamics and spatial structure are captured in a single scan.