A new study proposes a method to detect sub-eV axion dark matter using the chiral magnetic effect in Weyl semimetals. Axions, hypothetical particles that could constitute dark matter, would behave as a coherent classical field capable of inducing a macroscopic current in certain quantum materials. This proposal opens a promising experimental avenue for the search for these elusive particles.

The method relies on the chiral magnetic effect, a quantum phenomenon occurring in Weyl semimetals. Under a static external magnetic field, the presence of axions would induce a detectable electric current. Researchers demonstrate that, for a 1 cm² sample in a 10 T magnetic field, the expected signal would be in the femtoampere range, a magnitude that is observable with current technology.

Implementing this experiment, using state-of-the-art SQUID-based current readout systems, would allow probing axion-electron couplings below existing stellar cooling bounds across a broad range of axion masses. This would offer unprecedented sensitivity in the search for axionic dark matter. This advance could provide direct evidence for the existence of axions and shed light on the composition of the universe's dark matter.