Researchers at NIST have developed a quantum dot that helps scientists “see” quantum mechanics in action without disturbing the process. The quantum dot, made of indium gallium arsenide, was used in an experiment that recreated a historic two-slit experiment where light behaves as both particles and waves.
In the original experiment, measuring the position of a photon would disturb its momentum, making it impossible to determine which slit the photon passed through without changing the interference pattern. However, by using “weak measurement” techniques, researchers were able to gain some information about the photons’ paths without disturbing the interference pattern.
The NIST quantum dot was embedded in an optical cavity within a microscale pillar to direct photons in the desired direction. The dot was excited continuously by a laser and emitted an individual infrared photon each time it relaxed. By repeating the measurements many times and combining the results, researchers reconstructed the photons’ paths as they passed through the slits, as well as the probabilities of taking each path.
This research has provided new insights into the behavior of light and its dual identity as both particles and waves, potentially advancing our understanding of quantum mechanics and its applications in various fields.
Keywords: Interference, Photons, Quantum dot, Measurement
