German scientists have successfully frozen a beam of light for an entire minute “to ensure that it retains its quantum coherence properties (i.e. its information state), thus making it possible to build light-based quantum memory.” If further experiments are conducted to perfect the technique, it could allow for more secure quantum communications over longer distances. Continue reading for three fascinating videos on the speed of light and for more information.
Light is electromagnetic radiation that moves at 300 million meters per second. Over the course of a one minute span, it can travel about 11 million miles, or 20 round trips to the moon.
For this particular experiment, researcher Georg Heinze and his team converted light coherence into atomic coherences. They did so by using a quantum interference effect that makes an opaque medium – in this case a crystal – transparent over a narrow range of light spectra.
The researchers shot a laser through this crystal (a source of light), which sent its atoms into a quantum superposition of two states. A second beam then switched off the first laser, and as a consequence, the transparency. Thus, the researchers collapsed the superposition – and trapped the second laser beam inside.