Crystal Defects Mimic Elusive Theoretical Fractons

In physics, a model for one system can sometimes be mathematically mapped to a model for an entirely different system. The beauty of such a “duality” is that it allows a physical system to be pictured in an entirely different, often simpler, way. Michael Pretko and Leo Radzihovsky of the University of Colorado, Boulder, have now uncovered a visually striking duality in condensed matter physics [1]. The two researchers found a mapping between the theory for lattice defects in a 2D crystal (Fig. 1 and Fig. 2) and the theory for hypothetical particles known as fractons [2]. Fractons are expected to behave differently from the “regular” particles described by the standard model, and they might be useful for quantum computation. But they have remained an entirely theoretical construct. The existence of this duality means that some of the bizarre properties of fractons are potentially observable in crystal defects.