A symmetry-derived mechanism for atomic resolution imaging

An "image" is a representation of an object, providing information about its form and structure. In many imaging systems, image contrast arises when the object alters the energy, phase, and/or amplitude of the probing radiation. Here, we introduce an image contrast that arises when the object alters the symmetry of the probing radiation. We demonstrate this in scanning transmission electron microscopy, visualizing changes in object symmetry at the picometer scale. These atomic-resolution symmetry images provide information that can be important in understanding any material where symmetry plays a significant role, including symmetry-breaking events, such as point and planar structural defects, strain, and local electric and magnetic fields.