A major research challenge in the field of nanotechnology is finding efficient ways to control light, an ability essential for high-resolution imaging, biosensors and cell phones. Because light is an electromagnetic wave that carries no charge itself, it is difficult to manipulate with voltage or an external magnetic field. To solve this challenge, engineers have found indirect ways to manipulate light using properties of the materials from which light reflects. However, the challenge becomes even more difficult on the nanoscale, as materials behave differently in atomically thin states.