Electronics could work faster if they could read and write data at terahertz frequency, rather than at a few gigahertz. Creating such devices would be eased with materials that can undergo a huge change in how easily they conducted electricity in response to a magnetic field at room temperature. Scientists believe thin films of perovskite oxides hold promise for such uses. However, such behavior has never been seen at these frequencies in these films. Until now. Via terahertz pulses, scientists at Center for Integrated Nanotechnologies and the United Kingdom discovered colossal changes in electricity’s flow at the desired frequencies and temperature.