Figure 1

Figure 1: (Top) The string of defects (emphasized by blue halos) that are generated by hole motion in an antiferromagnetic background can be “healed” by quantum fluctuations. (Bottom) A similar string of defects (blue halos) is generated by zigzag hole motion in an alternating-orbital-order background (the green and purple lobes represent orbitals with xz and yz symmetry, respectively). These cannot be healed by quantum fluctuations and instead the hole has to do it by retracing its steps. Overall hole motion is enabled by three-site processes (red halos), consisting of directional tunneling through a doubly occupied site without generating a defect.