Atoms in a material are rarely still. They jiggle back and forth in collective lattice vibrations known as phonons. Their motion can also carry a rotational element: In 2023, scientists at PSI experimentally proved the existence of chiral phonons, which exhibit handedness depending on which way they rotate.

Now, the same team of researchers has shown that an applied electric field can control the handedness of these phonons. The research is published in the journal Nature Materials.