Aharonov-Bohm Effect in Neutral Excitons

  We have made the first experimental observation of the Aharonov-Bohm effect in neutral excitons. In classical mechanics the motion of an electrical charged particle is only affected if the particle enters a region of space with a magnetic or electric field. Meanwhile, in quantum physics, an electrically charged particle is affected by the magnetic potential in regions even if the magnetic and electric fields are zero in the region (Aharonov-Bohm effect). Several theory papers have discussed the plausible existence of the this effect even for neutral particles! We have confirmed this speculation.