U-M Physicists Steer Electron Beams With 2 Infrared Lasers, No Voltage Needed
Updated
Updated · ScienceAlert · Jul 26
U-M Physicists Steer Electron Beams With 2 Infrared Lasers, No Voltage Needed
2 articles · Updated · ScienceAlert · Jul 26
Summary
University of Michigan physicists built an “electron lighthouse” that emits a directional electron beam controlled by light alone, experimentally showing electrons can be steered without any applied electric field.
Two infrared laser beams drive the effect in a semiconductor, and rotating the light’s polarization rotates the beam—turning light from a simple on-off switch into a way to aim current.
The resulting signal is a ballistic current, meaning electrons follow launch trajectories instead of diffusing through repeated scattering; the team said detecting that current in the fabricated device was a key surprise.
Built at U-M’s Lurie Nanofabrication Facility and published in Physical Review Letters, the device was designed to avoid stray external fields that could distort the measurement.
The work confirms a prior theoretical prediction and could help probe quantum geometry in materials, with possible applications in quantum sensing, communications, imaging and computing.