Scientists have shown that applying an electric field can control the "handedness" of chiral phonons—vibrations in a material that have a directional twist, similar to the way a spiral can twist to the left or right. This discovery, published in Nature Materials, could lead to new technologies that use phonons—vibrational energy in solids—as a way to store and process information. The research builds on a 2023 breakthrough in which the same team experimentally confirmed the existence of chiral phonons for the first time. In their latest study, the researchers constructed a microscopic device using barium titanate (BaTiO₃), a material known for its ability to change its internal electric polarization in response to an electric field. Thin membranes of barium titanate, just 40 nanometers thick, were produced in Taiwan and fitted with small electrodes. These were placed on a silicon base to create a test platform. By flipping the electric polarization of the material—essentially switching its internal electric direction—the researchers observed that the handedness of the atomic vibrations, or phonons, also changed. More surprisingly, the new handedness remained even after the electric field was turned off. The process was done at room temperature using a voltage as low as 3 volts, making it potentially practical for future devices. To observe the phonons’ handedness, the team used circularly polarized X-rays at the European Synchrotron Radiation Facility. They employed a technique called resonant inelastic X-ray scattering (RIXS), which measures how angular momentum is transferred between the X-rays and the material’s lattice. This allowed them to detect the twist in the phonons’ motion. The ability to control phonon handedness using electricity opens up new possibilities for manipulating magnetic and electronic states, as phonons carry angular momentum that can interact with electrons and magnetic fields. This could lead to novel ways of controlling information in devices. Beyond practical applications, the study also touches on a deeper scientific question: why does chirality—directional asymmetry—exist in nature, particularly in biology, where molecules like DNA and proteins are almost exclusively "left-handed"? The connection between chiral phonons and magnetism may offer new insights into this long-standing mystery.