The optical glow of quantum crystals Researchers have developed a new method to reveal the collective motion of electrons in one of the most elusive states of matter: the Wigner crystal. Using light, the physicists were able to uncover previously inaccessible properties of this fragile quantum state. By illuminating the material and measuring the reflected light, the researchers observed new optical features that reveal the collective behavior of electrons within a Wigner crystal. The researchers used light to reveal the collective motion of electrons forming a Wigner crystal. The resulting hybrid quasiparticles, called Wigner crystal polarons, act as highly sensitive optical probe of the crystal and its collective dynamics.