Researchers at the University of Michigan have developed a semiconductor device that uses laser light to generate and steer a narrow beam of electrons without requiring an external electric field. By combining two laser beams of different colors, the team precisely controlled the direction of electron flow through a quantum interference effect, creating what they describe as an “electron lighthouse. Unlike previous approaches that used light only to switch electrical currents on, the new technique can also direct the current, opening new possibilities for controlling electrons with light alone. The breakthrough demonstrates a quantum phenomenon that had previously only been predicted in theory. The technology could support future advances in optical sensing, telecommunications, imaging, information storage, and photonic-electronic devices. While the work is currently focused on fundamental physics, researchers believe it could lead to faster and more efficient ways of transmitting and processing information.
